I've found that Schaum's study guides are great for learning mathematics on your own. Clear concise descriptions of how and why things work, and lots of sample problems. Oh, and do the problems man, do them all. You won't get good at math without lots and lots of problem solving experience.
Another great tool is Mathematica. It will do the problems for you, which you don't want to make a habit of. But, when you're stuck, it really helps out, and it will show you all the work. Mathematica helped me through many high-level math courses, but it's pretty spendy. If your daughter is in college, she can probably get you the student version for around $100 or so. I worked in the Mathematics department at a large university, so I had the full version to use for free since it was installed on all of their machines. It runs on Windows, Linux, and Mac OSX.
I'm sure there are people at MS who know enough about the device to do this. And since they probably make $45k a year plus stock options (which are in the toilet right now), there's probably a high probability that an MS developer is going to claim some of that cash, especially if he's able to remain anonymous.
I used WebTrends for several sites with about the same traffic you're looking at analyzing. In short, WebTrends sucks bigtime. It would crash for no reason almost everyday, and their dns resolver code is sloooooooow. I had to write a custom dns resolver that would replace all of the ip's with the hostnames in the logfiles before running it through webtrends. I've used both the Windows version, and the Linux Webtrends server. The windows version actually worked better, but it still sucked bigtime. Their customer support sucks too. A new version came out a week after I spent $2000 on their software, which was filled with bugs. The new version fixed most of the bugs, but they were going to make me buy it again to get the upgrade. Analog with Report Magic did the same things webtrends did, but it was free, and it worked much better.
Another package I've used is Accrue. I think this is by the same people that make HitList, but it's much better. It's not without it's problems, but it would work great for a site with the amount of traffic that you are analyzing. We didn't run into problems until trying to analyze more than 150 million hits/day. It has a sniffer that sits on your network and watches web traffic. It generates it's own logs which are more comprehensive than your webserver logs. Every hour, it uploads it's data to the "warehouse" box which analyzes it at the end of the day. It requires beefy hardware, big expensive Sun Enterprise systems. It has some nice marketing stats stuff, like path analysis, and other crap. Very expensive though, expect to spend 5 to 6 figures on the software, and another 5 to 6 figures on hardware. They purchased another company that did nearly the same thing about a year ago, and they have a new version based on the technology from the other company, version 6.0/6.1. I haven't used the new version, but supposedly it's much better. The price is still insane though, so unless this is something you really really need, I'd stay away. It also requires a good DBA who knows RedBrick or Oracle (you can use either for a database).
Another option is a managed log service like Digimine. They work well, but it's a recurring fee since it's a service, not software. And you have to upload your logs to them every day.
There's a company that's been hitting me up lately, I forget their name now. But they have a linux based version which has clustering capability. The database is stored compressed in chunks across the entire cluster. It scales linearly, so you can add machines as you need them. They've been taking business away from Digimine and Accrue. They are based in Minneapolis I think, but like I said, I forget their name now. Their software can correlate different logs together too, and get you stats on email campaign's, video streaming, and your webservers. If you're into spending money, this would likely be your best bet.
I would stay far far away from WebTrends if I were you. Webtrends is a sucky product, and you can get the same info with Analog and ReportMagic, for free, and with better performance. 1.8 million hits isn't really that much, so a product like Accrue would likely be overkill. And most companies balk at services since they can't depreciate the expenditure over time, it's an operating cost not a capital expense.
If you can't find what you're looking for with Linux or BSD, take a look at the Foundry ServerIron XL. It lists for $7995, but you can pick them up used for around $3000 each. The performance is way better than you'll see with a non-ASIC based platform, and it has more features than you'll find with a *nix solution. The foundry also does Global DNS load balancing if you have multiple different datacenters. At $3000, it's around the same price as a Dell 1650, which is what you'd need if you have a high traffic site (more than 80 or 90 Mbit/sec at any one time). I've been using Foundry and F5 for quite some time, and I have to say the Foundry definitely comes out on top, both in price and performance.
FYI, F5's insanely priced products are simply a heavily modified version of FreeBSD running a modified version of Bind 8.
Obviously, this should be a separate network, but for users to get access to the net, they should have to log in with their library card number and a password. The best way to do this would be to use a firewall that has captive gateway support. When the user tries to use a browser to go somewhere, the firewall intercepts the traffic and brings up a login page. This way, you get accounting information of who's using the network, and what they are doing. If you run into problems, you can go back on your logs and pin it down to the person who caused the trouble.
Netscreen makes a model called the 5xp. There's a $495 version that will allow 10 clients at a time behind it, and there's a $995 version that allows unlimited. It has the "captive gateway" code built in, and it can authenticate against a local database on the firewall, or a 3rd party RADIUS or LDAP server. I use several of these units and they are probably the most impressive piece of equipment for the money I've ever seen. The captive gateway stuff works sweet for wireless networks also (although I use one of their larger firewalls and put the WAP in a separate zone). I have a 5xp at home, and the sheer number of features it has well surpasses that of a $30,000 Cisco PIX.
Dammit. Why can't someone come out with something that has Vorbis support. MP3's sound like shit on my car stereo, the bass distorts way too easily. Vorbis sounds great, but I don't wanna carry a laptop around my car to listen to all my vorbis files.
The second someone releases a decent player like this with vorbis support is the second I fork over a few hundred bucks for one.
This is total BS. I installed it on two machines that only had floppy drives. There's no "official" way to do it, but all you need is a boot disk like Tom's root boot. Just boot, and follow all the instructions like you normally would with the cd, when it gets to the part where you copy the 16mb tarball to the hard drive, just ftp it down from somewhere. I've done it twice.
There's a similar product that doesn't require a laptop called SniperCue. I can't see these being used in real games, or especially tournaments. It might be a good learning tool to figure out how angles work, but it's not going to teach you english, and it's not going to teach you how hard to hit the ball.
Every cue is different though, even if they are the same model. If one learns on a cue like this, they are going to have to get the feel of the non-laser/camera cue before being much good. Plus, at over $1000, you could get a nice Schon Limited for less. I'll stick with my Joss, the more I play with that cue, the better I get with it.
There is that too, but I didn't think of it because I live in minnesota where winters are usually just as bad.
Of course, in ND, there are no trees to block the wind, so you get obscenely cold wind chills. And when the ditches fill with snow so they are level with the road, it's hard to see exactly where the road is if there is any snow on it. Driving off the shoulder into an 8 foot ditch isn't much fun when you break through the hard crust on top.
If only everyone could buy a box for their rooftop that did this via 802.11b or a. Internet in the hands of the people. The problem would be getting on the wired part of the internet, but if there was a way for big business to take a part in this, it would make it pretty cool.
Too bad the range is so low on 802.11. If you could get 100 mile links out of it somehow, there would be little need for wires.
All 600,000 residents are now protected! Actually, having lived in ND for a year and half, it's surprising that this actually happened. They ran ads trying to scare people saying it would keep business out of the state, and I've noticed that people there tend to believe everything they see on TV, and are very concerned about bringing more business to the state.
Of course, it's not privacy laws that are going to keep business out, it's the flatness, the lack of activities, and the high cost of getting a fat pipe that's keeping business away. Not to mention that if a business needs some piece of equipment in a hurry, it will take a couple days to ship it there since it's doubtful that it's available locally. I don't miss living there one bit, but it's good that they actually repealed this evil law.
Wow, I have a headache from just reading the front page and seeing those damn flashing banners. You can bet your sweet ass I won't be going back to that site anytime soon.
I'm looking for interesting books on the cold war. Primarily ones that deal with russian secrets, spying, and the "space race".
Some of the greatest technology ever made came out of the cold war, and it's interesting to see how a country essentially closed to the rest of the world can develop it's own version of a current technology that works in a completely different way.
Isn't this the same type of thing that NASA funded some guy several million to develop? It was on slashdot last year sometime. Apparently, they want him to build a giant rotating superconductor that would sit below the shuttle launchpad. Even if it reduced the effective mass by only a fraction of a percent, it would save huge amounts of fuel.
Actually, if you've already included a lockpick set, that may not be legal. In most states, it's illegal to own a lockpick set unless you have a locksmith license. In minnesota, this is definitely the case.
Actually, you can pick up a Samsung laser printer for around $170 (less on sale). Samsung has linux support for them also, and they print pretty decent quality also. Awhile back, Amazon.com had it for $150 with free shipping, and there was a mail in coupon for a free extra toner.
As far as color goes, I had a big dye sublimation printer that I picked up for $60. Printed photo quality on 8.5x11 paper. If you do some looking on ebay, you can find one of those for next to nothing. Although, I'm not sure how much the refills cost since mine came with 3 rolls. Even getting an inkjet for doing color might not be so bad since most people rarely print color.
But printing black and white on an inkjet is definitely not cheap.
The problem with comparing OS X with an intel server running windows is that companies buying windows servers are most likely tied to MS for some reason (.NET). I don't see the Xserve competing with a wintel box at all. However, I do see it competing with x86 servers running linux or a BSD variant, since OS X is a BSD variant in itself, porting apps to run on it should be trivial if not already done.
I work in a big windows shop, but we do have a lot of *BSD and linux stuff, and I have already looked into getting some Xserve's for future Unix needs. I have one OS X box now that I use for various things, and it's smokin' fast (only a G3 400). The pricing on the Xserve is maybe a bit better than Dell pricing, and I can get more drive space, perfect for a syslog server or an intrusion detection database.
The article really doesn't draw any conclusions but rather makes some obvious assumptions. I'd like to see some hard benchmarks to see how it compares against a Dell 1650.
One thing I did notice from the article is that the IBM servers have built-in 512MB ram. Why would they build it in? In a large server farm, the one thing that fails most often is memory. If this is built in, it's going to present a big pain in the ass to replace.
Why don't stations stream in multicast? True, many routers are not set up by default to route multicast and some firewalls will not pass it without some extra configuration, but a certain percentage of listeners could certainly utilize it. It would save a bundle on bandwidth costs both for the broadcaster, and for companies who have employees that listen to the stuff (about 20 people here stream music from SomaFM all day long). Multicast has been around forever, but hardly anyone uses it. The biggest app I know of that uses multicast is some crazy stock quote streaming program from dbc.com.
In all of the places I've worked, the biggest barrier to implementing password policies is the users. People want simple passwords because they are lazy, and they don't want to be forced to remember a new one every month. Management has an interest in not pissing off users as it makes them look bad, and if there was a breach of security, it would make the people under them look bad, not them.
I've found that the best way to convince management to allow password policies is to whack up some sort of brute force password cracker, and run it with them sitting right there. Scare them into it. Make lots of mention about all of the bad PR you'd receive if you were hacked and what your clients would think. This will usually sway them in the right direction. A much better system would be Secure Computing's Safeword product, one-time use passwords that are event based, not time based like RSA's product. This way users don't ever have to change their password, and if it gets sniffed over a silly telnet connection, the attacker can't use it for anything.
A few years ago, I had an account at a local ISP that offered shell access. Amazingly, they were not using shadow passwords even though that option was available at the time. I grabbed the file, and using my trusty 486, I cracked 4000 out of 6000 accounts in 2 weeks. I didn't do anything with the passwords I found, but someone more evil than me obviously could have.
John the ripper is an excellent tool, and will also work on windows passwords also with an addon.
While this law is cool, I wouldn't say MN has a clue. They are forcing everyone to pay for our new stadium by the imposition of a "sin tax". The tax is in effect on some stuff in Minneapolis now, and will roll out to the whole state by 2004. Tax is $1 on a bottle of beer, around $3.50 on a pack of cigarettes, $5 for a lap dance (I shit you not), and taxes on lingerie and other such things.
While it's true that you don't need to buy these things if you don't want to pay for the stadium, it sucks for those of us who regularly buy these things and could give a rats ass about the stadium.
They obviously aren't figuring inflation into this number. Wouldn't it be a little more accurate to list how many tickets were sold instead? Then the numbers could be compared against movies from years ago when it only cost $2-$4 for a ticket.
I think it's BS to say that "Movie X" is the biggest money maker of all time when movies used to cost 30% of what they do now.
You attach another cool chip to the back, obviously.
Actually, you can do this. It's a common technique used with peltier units. However, it only works up to a point, because the unit can only move a certain amount of heat, called Qmax. If you're moving 50 watts of heat away from a processor, an it takes 10 watts of electricity to run the cooler, the one you stack on top of it must have a Qmax greater than 60 watts or it will become an insulator. Now, you can get around this by attaching a copper or aluminum plate to the hot side, and sticking two more units (with a Qmax of at least 30 watts each) side by side on it. But, you still have to get rid of the heat somehow in the end. Usually if you're stacking peltiers, you need a *REALLY* big heatsink or water cooling. But peltiers are very inefficient, and if these claim 80% efficiency, you might be able to get away with stacking a bunch of them and still use a heatsink on it.
Slashdot Mirror
I've found that Schaum's study guides are great for learning mathematics on your own. Clear concise descriptions of how and why things work, and lots of sample problems. Oh, and do the problems man, do them all. You won't get good at math without lots and lots of problem solving experience.
Another great tool is Mathematica. It will do the problems for you, which you don't want to make a habit of. But, when you're stuck, it really helps out, and it will show you all the work. Mathematica helped me through many high-level math courses, but it's pretty spendy. If your daughter is in college, she can probably get you the student version for around $100 or so. I worked in the Mathematics department at a large university, so I had the full version to use for free since it was installed on all of their machines. It runs on Windows, Linux, and Mac OSX.
I'm sure there are people at MS who know enough about the device to do this. And since they probably make $45k a year plus stock options (which are in the toilet right now), there's probably a high probability that an MS developer is going to claim some of that cash, especially if he's able to remain anonymous.
I used WebTrends for several sites with about the same traffic you're looking at analyzing. In short, WebTrends sucks bigtime. It would crash for no reason almost everyday, and their dns resolver code is sloooooooow. I had to write a custom dns resolver that would replace all of the ip's with the hostnames in the logfiles before running it through webtrends. I've used both the Windows version, and the Linux Webtrends server. The windows version actually worked better, but it still sucked bigtime. Their customer support sucks too. A new version came out a week after I spent $2000 on their software, which was filled with bugs. The new version fixed most of the bugs, but they were going to make me buy it again to get the upgrade. Analog with Report Magic did the same things webtrends did, but it was free, and it worked much better.
Another package I've used is Accrue. I think this is by the same people that make HitList, but it's much better. It's not without it's problems, but it would work great for a site with the amount of traffic that you are analyzing. We didn't run into problems until trying to analyze more than 150 million hits/day. It has a sniffer that sits on your network and watches web traffic. It generates it's own logs which are more comprehensive than your webserver logs. Every hour, it uploads it's data to the "warehouse" box which analyzes it at the end of the day. It requires beefy hardware, big expensive Sun Enterprise systems. It has some nice marketing stats stuff, like path analysis, and other crap. Very expensive though, expect to spend 5 to 6 figures on the software, and another 5 to 6 figures on hardware. They purchased another company that did nearly the same thing about a year ago, and they have a new version based on the technology from the other company, version 6.0/6.1. I haven't used the new version, but supposedly it's much better. The price is still insane though, so unless this is something you really really need, I'd stay away. It also requires a good DBA who knows RedBrick or Oracle (you can use either for a database).
Another option is a managed log service like Digimine. They work well, but it's a recurring fee since it's a service, not software. And you have to upload your logs to them every day.
There's a company that's been hitting me up lately, I forget their name now. But they have a linux based version which has clustering capability. The database is stored compressed in chunks across the entire cluster. It scales linearly, so you can add machines as you need them. They've been taking business away from Digimine and Accrue. They are based in Minneapolis I think, but like I said, I forget their name now. Their software can correlate different logs together too, and get you stats on email campaign's, video streaming, and your webservers. If you're into spending money, this would likely be your best bet.
I would stay far far away from WebTrends if I were you. Webtrends is a sucky product, and you can get the same info with Analog and ReportMagic, for free, and with better performance. 1.8 million hits isn't really that much, so a product like Accrue would likely be overkill. And most companies balk at services since they can't depreciate the expenditure over time, it's an operating cost not a capital expense.
If you can't find what you're looking for with Linux or BSD, take a look at the Foundry ServerIron XL. It lists for $7995, but you can pick them up used for around $3000 each. The performance is way better than you'll see with a non-ASIC based platform, and it has more features than you'll find with a *nix solution. The foundry also does Global DNS load balancing if you have multiple different datacenters. At $3000, it's around the same price as a Dell 1650, which is what you'd need if you have a high traffic site (more than 80 or 90 Mbit/sec at any one time). I've been using Foundry and F5 for quite some time, and I have to say the Foundry definitely comes out on top, both in price and performance.
FYI, F5's insanely priced products are simply a heavily modified version of FreeBSD running a modified version of Bind 8.
Obviously, this should be a separate network, but for users to get access to the net, they should have to log in with their library card number and a password. The best way to do this would be to use a firewall that has captive gateway support. When the user tries to use a browser to go somewhere, the firewall intercepts the traffic and brings up a login page. This way, you get accounting information of who's using the network, and what they are doing. If you run into problems, you can go back on your logs and pin it down to the person who caused the trouble.
Netscreen makes a model called the 5xp. There's a $495 version that will allow 10 clients at a time behind it, and there's a $995 version that allows unlimited. It has the "captive gateway" code built in, and it can authenticate against a local database on the firewall, or a 3rd party RADIUS or LDAP server. I use several of these units and they are probably the most impressive piece of equipment for the money I've ever seen. The captive gateway stuff works sweet for wireless networks also (although I use one of their larger firewalls and put the WAP in a separate zone). I have a 5xp at home, and the sheer number of features it has well surpasses that of a $30,000 Cisco PIX.
Dammit. Why can't someone come out with something that has Vorbis support. MP3's sound like shit on my car stereo, the bass distorts way too easily. Vorbis sounds great, but I don't wanna carry a laptop around my car to listen to all my vorbis files.
The second someone releases a decent player like this with vorbis support is the second I fork over a few hundred bucks for one.
Don't even bother if you can't boot from CD
This is total BS. I installed it on two machines that only had floppy drives. There's no "official" way to do it, but all you need is a boot disk like Tom's root boot. Just boot, and follow all the instructions like you normally would with the cd, when it gets to the part where you copy the 16mb tarball to the hard drive, just ftp it down from somewhere. I've done it twice.
There's a similar product that doesn't require a laptop called SniperCue. I can't see these being used in real games, or especially tournaments. It might be a good learning tool to figure out how angles work, but it's not going to teach you english, and it's not going to teach you how hard to hit the ball.
Every cue is different though, even if they are the same model. If one learns on a cue like this, they are going to have to get the feel of the non-laser/camera cue before being much good. Plus, at over $1000, you could get a nice Schon Limited for less. I'll stick with my Joss, the more I play with that cue, the better I get with it.
There is that too, but I didn't think of it because I live in minnesota where winters are usually just as bad.
Of course, in ND, there are no trees to block the wind, so you get obscenely cold wind chills. And when the ditches fill with snow so they are level with the road, it's hard to see exactly where the road is if there is any snow on it. Driving off the shoulder into an 8 foot ditch isn't much fun when you break through the hard crust on top.
If only everyone could buy a box for their rooftop that did this via 802.11b or a. Internet in the hands of the people. The problem would be getting on the wired part of the internet, but if there was a way for big business to take a part in this, it would make it pretty cool.
Too bad the range is so low on 802.11. If you could get 100 mile links out of it somehow, there would be little need for wires.
All 600,000 residents are now protected! Actually, having lived in ND for a year and half, it's surprising that this actually happened. They ran ads trying to scare people saying it would keep business out of the state, and I've noticed that people there tend to believe everything they see on TV, and are very concerned about bringing more business to the state.
Of course, it's not privacy laws that are going to keep business out, it's the flatness, the lack of activities, and the high cost of getting a fat pipe that's keeping business away. Not to mention that if a business needs some piece of equipment in a hurry, it will take a couple days to ship it there since it's doubtful that it's available locally. I don't miss living there one bit, but it's good that they actually repealed this evil law.
Wow, I have a headache from just reading the front page and seeing those damn flashing banners. You can bet your sweet ass I won't be going back to that site anytime soon.
I'm looking for interesting books on the cold war. Primarily ones that deal with russian secrets, spying, and the "space race".
Some of the greatest technology ever made came out of the cold war, and it's interesting to see how a country essentially closed to the rest of the world can develop it's own version of a current technology that works in a completely different way.
Isn't this the same type of thing that NASA funded some guy several million to develop? It was on slashdot last year sometime. Apparently, they want him to build a giant rotating superconductor that would sit below the shuttle launchpad. Even if it reduced the effective mass by only a fraction of a percent, it would save huge amounts of fuel.
Legal items only, please
Actually, if you've already included a lockpick set, that may not be legal. In most states, it's illegal to own a lockpick set unless you have a locksmith license. In minnesota, this is definitely the case.
Actually, you can pick up a Samsung laser printer for around $170 (less on sale). Samsung has linux support for them also, and they print pretty decent quality also. Awhile back, Amazon.com had it for $150 with free shipping, and there was a mail in coupon for a free extra toner.
As far as color goes, I had a big dye sublimation printer that I picked up for $60. Printed photo quality on 8.5x11 paper. If you do some looking on ebay, you can find one of those for next to nothing. Although, I'm not sure how much the refills cost since mine came with 3 rolls. Even getting an inkjet for doing color might not be so bad since most people rarely print color.
But printing black and white on an inkjet is definitely not cheap.
Murray Cumming on Programming for GNOME with C++
I like programming for GNOME in C++ as much as the next guy, but Murray just needs to calm down a bit.
The problem with comparing OS X with an intel server running windows is that companies buying windows servers are most likely tied to MS for some reason (.NET). I don't see the Xserve competing with a wintel box at all. However, I do see it competing with x86 servers running linux or a BSD variant, since OS X is a BSD variant in itself, porting apps to run on it should be trivial if not already done.
I work in a big windows shop, but we do have a lot of *BSD and linux stuff, and I have already looked into getting some Xserve's for future Unix needs. I have one OS X box now that I use for various things, and it's smokin' fast (only a G3 400). The pricing on the Xserve is maybe a bit better than Dell pricing, and I can get more drive space, perfect for a syslog server or an intrusion detection database.
The article really doesn't draw any conclusions but rather makes some obvious assumptions. I'd like to see some hard benchmarks to see how it compares against a Dell 1650.
One thing I did notice from the article is that the IBM servers have built-in 512MB ram. Why would they build it in? In a large server farm, the one thing that fails most often is memory. If this is built in, it's going to present a big pain in the ass to replace.
Why don't stations stream in multicast? True, many routers are not set up by default to route multicast and some firewalls will not pass it without some extra configuration, but a certain percentage of listeners could certainly utilize it. It would save a bundle on bandwidth costs both for the broadcaster, and for companies who have employees that listen to the stuff (about 20 people here stream music from SomaFM all day long). Multicast has been around forever, but hardly anyone uses it. The biggest app I know of that uses multicast is some crazy stock quote streaming program from dbc.com.
In all of the places I've worked, the biggest barrier to implementing password policies is the users. People want simple passwords because they are lazy, and they don't want to be forced to remember a new one every month. Management has an interest in not pissing off users as it makes them look bad, and if there was a breach of security, it would make the people under them look bad, not them.
I've found that the best way to convince management to allow password policies is to whack up some sort of brute force password cracker, and run it with them sitting right there. Scare them into it. Make lots of mention about all of the bad PR you'd receive if you were hacked and what your clients would think. This will usually sway them in the right direction. A much better system would be Secure Computing's Safeword product, one-time use passwords that are event based, not time based like RSA's product. This way users don't ever have to change their password, and if it gets sniffed over a silly telnet connection, the attacker can't use it for anything.
A few years ago, I had an account at a local ISP that offered shell access. Amazingly, they were not using shadow passwords even though that option was available at the time. I grabbed the file, and using my trusty 486, I cracked 4000 out of 6000 accounts in 2 weeks. I didn't do anything with the passwords I found, but someone more evil than me obviously could have.
John the ripper is an excellent tool, and will also work on windows passwords also with an addon.
Finally a state with a clue.
While this law is cool, I wouldn't say MN has a clue. They are forcing everyone to pay for our new stadium by the imposition of a "sin tax". The tax is in effect on some stuff in Minneapolis now, and will roll out to the whole state by 2004. Tax is $1 on a bottle of beer, around $3.50 on a pack of cigarettes, $5 for a lap dance (I shit you not), and taxes on lingerie and other such things.
While it's true that you don't need to buy these things if you don't want to pay for the stadium, it sucks for those of us who regularly buy these things and could give a rats ass about the stadium.
They obviously aren't figuring inflation into this number. Wouldn't it be a little more accurate to list how many tickets were sold instead? Then the numbers could be compared against movies from years ago when it only cost $2-$4 for a ticket.
I think it's BS to say that "Movie X" is the biggest money maker of all time when movies used to cost 30% of what they do now.
You attach another cool chip to the back, obviously.
Actually, you can do this. It's a common technique used with peltier units. However, it only works up to a point, because the unit can only move a certain amount of heat, called Qmax. If you're moving 50 watts of heat away from a processor, an it takes 10 watts of electricity to run the cooler, the one you stack on top of it must have a Qmax greater than 60 watts or it will become an insulator. Now, you can get around this by attaching a copper or aluminum plate to the hot side, and sticking two more units (with a Qmax of at least 30 watts each) side by side on it. But, you still have to get rid of the heat somehow in the end. Usually if you're stacking peltiers, you need a *REALLY* big heatsink or water cooling. But peltiers are very inefficient, and if these claim 80% efficiency, you might be able to get away with stacking a bunch of them and still use a heatsink on it.
Wow, this is a much better solution than I've been using, and much less bloody.