Well, it certainly would slow the earth down, but as Amos says: not very much. I personally favour just using less power, which is another way of looking at the problem. Turn your heating down a notch, put an extra jumper on. Insulate your house. Dont drive around so much. Dont eat foetal peas flown in from outer Gombolia. All that obvious stuff.
    But wind-up cars is obviously a usefuk thing to look into, possibly with the assistance of Sir JOhn from Hull's hamsters and asylum New Seekers.