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Instructables has a very nice key holder/thing made from a bicycle multi-tool. It doesn't have the nice Leatherman pliers but personally I prefer it. http://www.instructables.com/id/Friendly-Folding-Keychain/

At the risk of getting modded down further I'm going to post a few links. Either of my recommendations will require you to reduce your number of keys but it's definitely worth it. I use the leatherman hack myself with my car key, my house key and my office key and then keep everything else in my car. http://www.instructables.com/id/Swiss-Army-Keys-Key-and-Leatherman-Mod/ http://www.gmtplusnine.com/2007/08/13/japan-made-key-holder/ (Very nice key holder made by a pair of watch makers, you'll pay for it though)

But there are a bunch of really old people who can't open a can with one of those, because they can't squeeze anything that tight. Remember, child-safe caps are beyond them. Several companies make little wrenches for their removal for this reason and people even share tips on instructables because it is such a real issue. Some people really need electric can openers if they're going to eat food out of a can. In our society which makes shopping a PITA, we don't shop daily, or (often) take care of our forebears, so the elderly are likely to need preserved foods. (ObDisclaimer: I'm certainly not taking care of my parents, they'd better lay in that Campbell's now. And a sturdy electric can opener, if they can find one.)

OK how about I redeem myself with Doc Brown

Yea, that's better.

I haven't done much hacking in a long tyme, years, myself. About all I do is cooking and gardening. So I've been thinking of combining electronics and gardening. Makezine printed an article on using a Garduino microcontroller to garden. It measures how much light and water plants get and if needed will turn on grow lights or a water pump. It's a bit late for this year though. Now what I'd do if I had a greenhouse would be to add heating, preferably geothermal, then I could add a month or two to garden.

Falcon

Lots of working models. Even some you can build.

The problem is that everyone focused on hydrogen because they sorted that energy density page by mass, not by volume. It's a very poor fuel. People are too focused on hydrogen IMHO. The best and cheapest methods so far considered to store hydrogen (reacting water with metal) all lead to the conclusion that metals are better. The fact that people have made metal air cells in their house that actually power things also shows that they are better.

Metal-air batteries work, and so does electrolysis to regenerate the batteries. The problem most of the companies I've seen so far hit has been the process of pumping the solid fuels ("pumping iron"). I'm a highschool student, so don't take my word for it. I'm also a roboticist, and so I think that if I can get the chemistry working, I can build robots to deal with fuel handling.

Lots of working models. Even some you can build.

The problem is that everyone focused on hydrogen because they sorted that energy density page by mass, not by volume. It's a very poor fuel. People are too focused on hydrogen IMHO. The best and cheapest methods so far considered to store hydrogen (reacting water with metal) all lead to the conclusion that metals are better. The fact that people have made metal air cells in their house that actually power things also shows that they are better.

Metal-air batteries work, and so does electrolysis to regenerate the batteries. The problem most of the companies I've seen so far hit has been the process of pumping the solid fuels ("pumping iron"). I'm a highschool student, so don't take my word for it. I'm also a roboticist, and so I think that if I can get the chemistry working, I can build robots to deal with fuel handling.

Lots of working models. Even some you can build.

The problem is that everyone focused on hydrogen because they sorted that energy density page by mass, not by volume. It's a very poor fuel. People are too focused on hydrogen IMHO. The best and cheapest methods so far considered to store hydrogen (reacting water with metal) all lead to the conclusion that metals are better. The fact that people have made metal air cells in their house that actually power things also shows that they are better.

Metal-air batteries work, and so does electrolysis to regenerate the batteries. The problem most of the companies I've seen so far hit has been the process of pumping the solid fuels ("pumping iron"). I'm a highschool student, so don't take my word for it. I'm also a roboticist, and so I think that if I can get the chemistry working, I can build robots to deal with fuel handling.

Lots of working models. Even some you can build.

The problem is that everyone focused on hydrogen because they sorted that energy density page by mass, not by volume. It's a very poor fuel. People are too focused on hydrogen IMHO. The best and cheapest methods so far considered to store hydrogen (reacting water with metal) all lead to the conclusion that metals are better. The fact that people have made metal air cells in their house that actually power things also shows that they are better.

Metal-air batteries work, and so does electrolysis to regenerate the batteries. The problem most of the companies I've seen so far hit has been the process of pumping the solid fuels ("pumping iron"). I'm a highschool student, so don't take my word for it. I'm also a roboticist, and so I think that if I can get the chemistry working, I can build robots to deal with fuel handling.

If it makes you feel better, I think I've never eaten Doritos.

Of course you have. What do you think Dorito Pie is made from?

The Forrest Mims books were great when I was a kid. I found them hanging in the back at Radio Shack.

It's worth noting that you'll often hear "The Art of Electronics" referred to as "Horowitz and Hill". I would second this book as a great way to start learning electronics as an adult, though it is a bit more theory and less practice. I would argue that if you're just "building stuff" without really understanding the principles behind it all, you're not really "learning electronics" any more than building a model kit airplane is "learning aerodynamics".

But as far as learning the implementation goes, yeah, I would say just start building stuff. Hit up Instructables and start small.

Try This.... http://www.instructables.com/id/Real_time_Web_Based_Household_Power_Usage_Monitor/

Combined with this.... http://www.instructables.com/id/2-Carabiner-split-core-AC-transducer/

And you've got it.

Try This.... http://www.instructables.com/id/Real_time_Web_Based_Household_Power_Usage_Monitor/

Combined with this.... http://www.instructables.com/id/2-Carabiner-split-core-AC-transducer/

And you've got it.

There are always alternatives. Like this nifty thing that runs on 2 AA batteries and has no memory or software. Sure, you'll need to get an additional $40 or so of equipment (soldering iron, clamp), but like OSS and food you make from scratch, you know exactly what's going into it.

And, for bonus points, you can expand this USB power supply with neat things like lithium-polymer batteries, USB charging, and even solar cells.

It is possible that he wants to achieve something similar to Burning visible images onto CD-Rs with data (beta)

Hey, if you want gigantic and not stylish, check this puppy out!

If you want folks to use something that isn't "closed", then make it better than Eagle and have documentation that shows us how to make better stuff with it.

Right now, I can download eagle, find a bunch of "directed at n00bs" guides that take baby steps to end up at a fully functioning ready-to-send-off set of files. Just look around.

gEDA's website, on the other hand, has three links to tutorials, two of which are broken, and one that breezes through a lot of things. You want folks to use it? Cater to the baby steps and release good guides.

As a side note, there is plenty of images of the schematics for this project. You don't need eagle for that.

The logic of the hardware is free for anyone to use. There is nothing stopping you or me from taking her work and cranking monchrons out in our own form.

If you want folks to use something that isn't "closed", then make it better than Eagle and have documentation that shows us how to make better stuff with it.

Right now, I can download eagle, find a bunch of "directed at n00bs" guides that take baby steps to end up at a fully functioning ready-to-send-off set of files. Just look around.

gEDA's website, on the other hand, has three links to tutorials, two of which are broken, and one that breezes through a lot of things. You want folks to use it? Cater to the baby steps and release good guides.

As a side note, there is plenty of images of the schematics for this project. You don't need eagle for that.

The logic of the hardware is free for anyone to use. There is nothing stopping you or me from taking her work and cranking monchrons out in our own form.

Did you see the laser guitar at instructables.com yet? http://www.instructables.com/id/The-Prism-A-Laser-Synth-Guitar/
Not really as advanced as MISA but seems to fit the theremin bill.

If you're handy with a soldering iron the you should build this nifty Seismic Reflector. From the website...

This project has two strands, a software and a hardware component. The aim is to build a device which responds to earthquakes being reported in near-real time via the USGS RSS feeds. The device responds by illustrating the magnitude of the reported earthquake via two fairly chunky vibration motors of the kind used in video game controllers. The device is connected to a PC via a virtual com port over USB (thanks to an on board Arduino). On the PC, an application sits there checking the RSS feed periodically and when a new event it posted to the RSS feed, the desktop app parses the data out of it and presents the magnitude of the quake to the Arduino which interpreters this as rate at which to activate the vibration motors.

I've seen stuff about people using woks and TV satellite dishes to boost signal power, so there's nothing surprising about saucepans doing it too. I'd be interested to see a comparison of these improvised devices with "proper" boosters. Would I be better off saving my money and just rigging up an old wok instead?

The obvious method to override.

Like this old-fashioned one!

There's a guy on instructables has done a sort-of little one with a flyback transformer.

http://www.instructables.com/id/Build_A_Plasma_Speaker/

Steve

It's still not counting, though it can reproduce the effects. A calculator doesn't actually count (it's just bit switching), but it reproduces the effect. Granted it means that whatever it's doing can simulate the effect of basic counting, but it in no way represents the understanding of numbers

Well, this is science. These researchers had a hypothesis that ants can count and devised an experiment to test the hypothesis. Based on their assumptions, the evidence from the experiments support their hypothesis.

Your hypothesis is that it's not counting but something else. It seems the next step is for you to devise a way to isolate counting from doing a counting-like behavior in ants and do an experiment to test your hypothesis.

However in a way, you're just playing with the definition. What does "understanding of numbers" mean? And is it really integral to counting? If you use pacecounter beads (Ranger beads: http://www.instructables.com/id/Army-Ranger-Beads/), you are "counting" on a piece of string but not actually keeping numbers in your head. In fact, the whole point of those is that you don't have to keep track of numbers because it's hard to do when you're exhausted and have all the other soldier-things to keep track of. You could use these beads to go out some distance, turn around and come back the same distance. You wouldn't have to use numbers in your head, but counting is still being done.

A lot of the "adapters" you get to change European current to our 115 Volt tell you straight-up that they shouldn't be used for electronics. They aren't kidding.

The best answer is to buy (or build) a charger that accepts batteries and has a suitable adapter. I just bought one for $25 for my Palm PDA that came with about a dozen different output jacks. It accepts two AA batteries, which can be bought just about anywhere in the world.

Here's a couple of options for the home-built version:

http://www.aarondunlap.com/blog/1130885615 http://www.instructables.com/id/MintyBoost!---Small-battery-powered-USB-charger/

By all means! The basics are here: http://www.instructables.com/id/Build-A-Motorized-Window-Blinds-Controller-For-Les/

Biochemtronics is the man for posting that. My notes on modifications are in the comments.

Good hunting!

How does this do anything at all to prevent a determined cheater? If you have the genuine Microsoft-branded XBox 360 hard drive, you can open it up and it's just a plain old SATA drive inside - which you can then proceed to plug into any computer. Or if you have the Official Microsoft memory stick, there exists a way to add a USB connector - at which point it's just mass storage.

It's a money grab, plain and simple. $99 for a 60GB 2.5" hard drive with some plastic around it? Piss off, Microsoft - in the computer world, $99 will get you 500 GB in a 2.5" drive without trying. The prices on their brand of flash memory are even more atrocious. $30 for 512 megs? Again, in the computer world that's 16GB in a USB key, which is what the XBox memory stick is, with added plastic.

To follow the thought.
http://www.instructables.com/id/Mouse-Mouse!/

The Kindle charges from USB, doesn't it? Would something like this do the trick?

If you are looking for "home grown technology", Instructables is pretty much your wet dream.

I'm considering the Wii-mote smartboard and multitouch displays, but I'm afraid I'm overreaching."

Not necessarily overreaching (I guess it depends on their prior experience), but those projects, while they have a definite "cool" factor, aren't particularly useful.

Personally I would stick to teaching them more useful stuff... maybe basic repair of electric appliances, or if you want something more advanced and that has both the cool factor and would be useful (at least to some people), maybe this DIY book scanner.

This is a very cool and ambitious project. Not a trivial build, just complex.

Now that Instructables has gone to a pay for download content model, maybe someone with a pro account wouldn't mind hosting the PDF of the build somewhere? (Apparently sharing is perfectly withing the realm of their TOS...)

Too late.

Some guy posted a great instructables on building your own high speed book scanner, purposely designed to rapidly photograph book pages without curves. He even includes a software stream that OCRs the contents and sticks them into PDFs.

It's been quite popular -- so much so that he's created an online forum at http://www.diybookscanner.org/ dedicated to discussions from DIY book scanners all over the place, where they talk about builds, parts, and software.

I've been very tempted to build one myself just to avoid carrying heavy books around in my backpack.

Some guy posted a great instructables on building your own high speed book scanner, purposely designed to rapidly photograph book pages without curves. He even includes a software stream that OCRs the contents and sticks them into PDFs.

It's been quite popular -- so much so that he's created an online forum at http://www.diybookscanner.org/ dedicated to discussions from DIY book scanners all over the place, where they talk about builds, parts, and software.

I've been very tempted to build one myself just to avoid carrying heavy books around in my backpack.

Actually, it's only the installer of XP that requires 64 MiB RAM.

XP will gladly boot in 18. Now, you better have a good hard drive, because it'll be thrashing the HELL out of it swapping.

(That also reminds me, it's also been booted on a Pentium I underclocked to a 40 MHz FSB, and an 0.5x multiplier - 20 MHz. XP REQUIRES a Pentium, IIRC, the guy who originally discovered that it'd work in 18 had to use a Pentium Overdrive in a 486 mobo, and tried swapping back to a 486, and got a BSOD on boot.)

Yeah maybe it's stupid but I want DRM-less access to books, it doesn't matter if the terminal has no net connection, as long as a I can do analysis on it.

Mmm, QR codes, I've tried that, turns out taking good quality photos of a screen is harder than it looks.. :-) Meaning it's almost easier to photograph-scan a book than to use QR-code. (Though I've only did the QR thing for 10 minutes, and I've spent 10 days scanning books with a camera, so I guess it will probably work if you spend some time on it).

I bet this mouse can also work on grass.

http://www.instructables.com/id/Hidden_USB_Storage/

you say impractical. i say a pr0n stash in each room with an rj-45 socket!

The truth is that ~70% of the energy stored in gas is heat, ~30% is expansion. The internal combustion engine uses the expansion of gasses, and then uses energy to throw away the heat.

So a gasoline engine only uses ~30% of the potential energy in gasoline, wasting the other 70% as heat?

Sounds like it's time for a Seebeck unit to use the Thermoelectric effect to get electrical power from waste heat.

Come to think of it, I'd like to see one in my laptop in between the CPU and heat sink. Talk about great battery life!

Running wire shark on the computer that might be infected is useless. Really nasty malware has the ability to hide it's traffic even from packet sniffers on the local host. I find the best bang for the buck is using a passive network tap and plug a sniffer into that. Now.. no need to go out and buy one as that will be expensive.. you can build one($18). http://www.instructables.com/id/Make_a_Passive_Network_Tap/ If you want to one-up this then get pc and install a network-based Intrusion Detection System(IDS), google snort, it'll look for abnormal network traffic patterns, and you can even configure them to notify you if it does detect something. Also.. take that linksys router and install DD-WRT on it and configure the firewall to block everything except what you know to be okay. Note: you can disable the reset button in DD-WRT =)

You can always use a splitter. It has one male and two female ends.

Can't find one? Then splice some Cat wire together

Just as a note, New York has bar codes on their driver licenses.
http://www.instructables.com/id/Decode-Your-License/

You're still quite correct in that they can't be read in your wallet, but that what RFID blocking wallets are for anyway.

Have customers just select a password for each account. Retailers would verify the password the same way they verify CSC numbers now,

Visa and Mastercard have already implemented this option. The only problem is the store has to be capable of handling it, and not all of them are, unfortunately.

https://usa.visa.com/personal/security/vbv/index.html?ep=v_sym_verified
http://www.mastercard.com/us/personal/en/cardholderservices/securecode/index.html

The account number is simply placed on the card, and authentication comes from physical ownership of the card. (PINs don't count because they are unfortunately verified based on machine-readable information on the card itself.)

This is wrong. PINs haven't been stored on the card for a long time (I'm not even certain they ever were for all cards). You can easily check this yourself with a relatively cheap reader, or you can build one yourself.

Wow, cool thought!! You heard it here first:
The Baghdad Battery, another ancient mystery device which dates to almost exactly the same time as the Antikythera Mechanism, performs well enough to drive a Homopolar Motor

Firstly its not clear at all whether the Baghdad Battery was meant to produce electricity, or whether it was a simple storage jar that happened to be from two metals. Secondly, the article you quote on building one says things like "charge at 1.1 to 1.5 V and a few milliamps of current", so good luck bootstrapping your Baghdad Battery charger bank when your only source of electricity is the occasional thunderstorm. Thirdly, good luck building your hompolar motor from naturally-occuring magnetic lodestones when you don't have fancy neodymium magnets around. So yeah, I heard it here first, and now I will go forget it again, wake me up when you have these little issues sorted out.

The prior devices and knowledge also come to mind. The crafts, arts, maths and sciences leading up to this must have included similar devices, possibly going back much farther. As well, other fine geared devices are likely.. I wonder what other similar mechanisms would be useful in the ancient world?

Wow, cool thought!! You heard it here first:
The Baghdad Battery, another ancient mystery device which dates to almost exactly the same time as the Antikythera Mechanism, performs well enough to drive a Homopolar Motor (very cool video link). I believe that there is no actual evidence of a handle with the Antikythera Mechanism, but simply an input shaft with a coupling. If I remember correctly, one turn of the shaft advanced it one day. I'll bet that a homopolar motor could accumulate enough power over a day to drive the Antikthera device.

Now the homopolar motor in its simplicity could easily be missed as a ancient device, or its 2 useful components (wire and magnet) scavenged for another use, leaving no artifact to find. Finally, here is a variable speed homopolar motor video I know I'm synthesizing the electric motor invention.. its just so simple that its invention at that time is possible, let alone any other type of motor. And an voltage/amperage controlled speed regulator seems likewise possible.

Found this, looks interesting for the DIY type.

http://www.instructables.com/id/Make-your-own-remote-power-switches/

there was this instructable cable organiser http://www.instructables.com/id/The-IKEA-charging-box---no-more-cable-mess!-Very-e/ (a closed plastic box containing powersockets and had a few holes in it so you have a dust-proof container with just a few small adapter plugs coming out. The only problem i have with a solution like that is that you cannot individually switch te adapters on and off. But, if you build your own set of powersockets and add a powerswitch for every socket ( by british example ). you can save clutter and money (and heat for that matter) When i move i am planning to build a cabletree inside a PVC pipe (sewer / rainpipe)

Of course, the problem is that I don't know of anyone who can comfortably solder BGA chips.

People have been doing it with toaster ovens (http://www.instructables.com/id/Toaster-Oven-Reflow-Soldering-BGA/ and http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=60&page=). I haven't tried that yet. I have soldered QFNs by laying down some solder paste and blasting the other side of the board with a heat gun, but it's a high-pucker-factor operation. I plan to try the toaster oven hack the next time I need to do that.

The problem with the Theremin is that to make a working example based on the principle of the original (capacitive coupling between the hands and antennas changing the frequency of an LC oscillator) is actually a fairly complex project - you have to understand about how LC oscillators work, the superheterodyne principle (the pitch oscillator is the difference frequency between a fixed and variable RF oscillator), transistor amplifier principles, etc. Of course, they can be built from kits, but just building from a kit doesn't really provide any insight into the functioning of the circuit.

A project that maintains the spirit of the original but might be easier for 9th graders to get a handle on might be the optical theremin. It only uses a few parts, and the basic operation of the 555 timer and light dependent resistance should be approachable for newcomers to electronics.