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High powered LED flashlights of the Luxeon, Fenix and Inforce (among others) families use timer circuits to oscillate between multiple beam elements to produce high efficiency and very bright emitters, that are capable of draining every erg from the battery.

source: I use tactical equipment. Efficiency and ruggedness is key. Keep your 5D Maglite.

The linked device is the bare LED, if you buy from that site you'll require a driver IC as well, otherwise a direct connection to a power source will cause momentary lasing before the emitter burns out. The IC prevents burnout and lasing (hence also takes the emitter out of the laser class of consumer devices).

If you're in the UK, you might also want to look at Maplin Electronics
mmm I do sometimes use them when i'm in a pinch. the big problem with maplin is that thier range of components has got worse and worse over the years. I do still sometimes use them in a pinch though.

they were even willing to sell single resistors for 7p each, rather expensive for a resistor,
seems they have gone up to 17p. Buy 10 at that price and you are up to nearly what rapid want for 100 equivilent resistors*

because you don't have to buy thousands at a time
Thousands is a bit of an exaggeration but yeah resistors do tend to come in fairly high quantities (50-100 is a typical pack size).

A bigger problem is minimum order values and/or small order charges. It's fine when your buying everything for project at once but a real pain when I just want one or two components for a hobby project**.

When it comes to prototyping resistors i've found the best thing to do is to get a resistor kit, for prototyping resistors e.g. http://www.rapidonline.com/Electronic-Components/Resistors-Potentiometer/Metal-Film-Resistors/MR25-Metal-film-resistor-kit/65199 .

P.S. I didn't mention maplin or rapid in my previous post because the subject at hand was micrcontrollers and afaict both maplin's and rapid's ranges of microcontrollers seem pretty absymal.

* The resistors maplin sell are actually relatively high spec having a power rating of 0.6W (in the conventional 0.25W body size) and a tolerance of 1%, if all you really needed was a cheap carbon film then maplin's price looks even worse.

** when doing stuff for the uni the uni hs deals that get us out of things like minimum order values and small order charges as well as getting us pretty steep discounts

The alternator doesn't care, but your MPG suffers every time the alternator spins. You can get quite a few more useful HP out of an engine if you remove the alternator completely. And if the rest of your claptrap were true, manufacturers would not be using LEDs in tail lights, dashboard instruments, turn signals etc etc. Less demand means smaller alternator, means more useful power to the wheels, means more MPG.

As for TTL, bollox mate.
http://www.rapidonline.com/Electronic-Components/Optoelectronics/Miniature-Lamps/Sixcess-LED-Lamp-12V-white-E12/75832/kw/12v+led
http://www.rapidonline.com/searchresults.aspx?style=0&kw=12v+led

The alternator doesn't care, but your MPG suffers every time the alternator spins. You can get quite a few more useful HP out of an engine if you remove the alternator completely. And if the rest of your claptrap were true, manufacturers would not be using LEDs in tail lights, dashboard instruments, turn signals etc etc. Less demand means smaller alternator, means more useful power to the wheels, means more MPG.

As for TTL, bollox mate.
http://www.rapidonline.com/Electronic-Components/Optoelectronics/Miniature-Lamps/Sixcess-LED-Lamp-12V-white-E12/75832/kw/12v+led
http://www.rapidonline.com/searchresults.aspx?style=0&kw=12v+led

Check this out. I think I'd have loved that at 13 (had a Sinclair ZX81 at that age), and it's very appealing even today, though I don't think I'll have the time to play with it seriously, so haven't bought it. There's a site for this (mentioned on that page) with extra games and apps with source code.

maplin suck nowadays. Thier prices are high and thier range has got shittier and shittier over the years. They still have a few kits from velleman but the huge range of maplin own brand kits is long gone :(.

For buying electronic components in the UK rapid ( http://www.rapidonline.com/ ) farnell ( http://uk.farnell.com/ ) and cpc ( http://cpc.farnell.com/ ) are your best bets. Rapid also have some kits availible mainly from velleman. (OT: they are also a good place to buy lego mindstorms stuff).

If you are going to order a lot of stuff and are prepared to wait digi-key are also a good bet. They are in the USA but provided your order is over a certain size (i think it's about £100) delivery and associated charges are included, thier prices are good and so is thier range.

searching for big capacitors on froogle, I came up with a link from Autotoys for a 1 Farad capacitor, on sale for a mere $42

Uh... the reason these capacitors are so expensive is because they're being sold to the car-modding community, who are generally willing to pay over-the-odds for something that looks flash. I bet they have blue leds and voltage displays on them. Capacitors sold for other purposes are generally cheaper.

As an example, this 10 farad 2.5v capacitor provides around a third the charge-holding capacity for roughly a tenth of the price.

you'd need a TON to power a car for an hour.. 100 HP = 75kW, for an hour, that's 270 MJ

Uh-huh.

1 - most cars don't need anything like 75kW. My old Ford Escort has a 56 kW engine and moves more than adequately. A small car (e.g. a Smart) would need substantially less.

2 - most people don't drive with their foot flat to the floor most of the time.

3 - electric motors have a much flatter torque response than internal combustion engines, which typically only provide half their maximum possible power at their normal operating point (you have to redline them on the gear changes to get best performance). Electric cars typically outperform internal combustion driven cars with much larger engines.

4 - a capacitor powered car would probably be better at regenerative braking than a battery powered one, so would need less charge overall anyway.