It is a good idea. In India we have washing machines which arepedal driven, just like a bic. I came with a similar idea tocharge cell-hones on the move, check out: http://www.whynot.net/ideas/4064. Keep brain stroming youngster it should stimulate yourcreative nerve.

Some of the machines at the gym employ that idea i think, as when you start to use them there is a slight delay until the LCD screen shows any data. Good thought tho.

I heard someplace did a concert, where the audience had pedal bikes to run the PA gear and such.

1 person = 1 horsepower = .75kw = 4.5 cents an hour where i live

It has been done, check out: http://www.prakruthipower.com/

I agree with this more on the premise of weight loss than on the premise of energy efficiency. I have often thought that if people bought a television for example that required a certain amount of physical energy input from the viewer via stationary bycycle or other means it would increase the daily calorie burn in a way that would also be rewarding and possible relaxing depending on the motions involved (don't bother - I already thought of the dirty joke that last sentence calls for.)