[EOD guy]

I was actually just thinking about this, and JUST had the idea (after watching Obama get elected) so I haven't figured out ANY specifics yet, but bare with me for just a little bit. I was looking at windmill generators on eb@y, and because they are permanent magnet motors, they can be used as generators or motors, and although they only produce a measly 300 to 1000 watts when hooked up to a wind turbine, they are only spinning at roughly 600 rpm or so, at their fastest. They are capable of spinning at roughly 7,000 RPM, and creating up to 130v DC intermitantly (sp?) Now lets look at some batteries. *edited several days after posting* Capacitors. No batteries, JUST capacitors. It seems everyone is hung up on my mention of batteries. What if I were to use a couple enormous capacitors?

Alright, so far we have motors, generators, and batteries. Now, how to spin the generators. I was thinking something along the lines of a small tire, like from a go cart, or an ATV, and more or less a home brew landing gear system. If you stick a motorcycle sprocket on there from an old beat up dirt bike, and a motorcycle chain, especially if you gear it UP rather then down, you could put a linear actuator under your car, have it activate with the brake switch (the switch that turns your tail lights on) lowering your landing gear, which through a sprocket and chain, spin your generator(s) If you need more braking power, push your brakes in further. They still work after all. Now your generators are charging your batteries. If it doesn't slow you down enough, or create enough voltage, stick another generator in there. Or a bigger one. Or put smaller gears on the gens or a larger gear on your landing gear (I don't know why I like to call it a landing gear so much, but I think it would be fun to tell people about the landing gear on my tacoma). Now we get into wiring just a little bit. You would have two sets of wires, and two sets of some powerful diodes running from your gen/motors to your bats. In braking mode, you allow current to go from your generators to your batteries. In taking off mode, you allow current to go from your batteries to your motors. Q:wouldn't you need a giant switch to carry all that amperage? You're gonna burn your car down loser! A: No, we need a small switch to operate a solenoid. So when you decide to take off, you push a button, and you start moving. At about ten or 15 MPH, start giving your car a little gas, and retract your landing gear.
So, that's my theory. The major problems that I can see is ensuring your batteries stay charged, ensuring that your batteries stay healthy, and charging your batteries quick enough (can you tell I don't know a whole lot about batteries?). One possible answer to charging the bats qickley, would to possibly get some big, bad, capacitors, which are designed to charge, and discharge extremely fast. But I know even less about capacitors then I do about batteries. There are a lot of technical problems, but all in all, I think this can be done.
Now to figure out how to make my wife thinks she's seen a flying pig... (that's when I get to visit the playboy mantion!)