I've been keeping my eye on alternative energy sources for a while and this seems to be the coolest:Japanese inventor Kohei Hayamizu has a vision: a city that is in itself an electric power station. A place where all its roads, bridges and sidewalks generate electricity from the vibrations produced by the cars and people that move over them.
They are already testing it on a busy sidewalk in the city, successfully creating energy when people walk over it. I couldnt embed the video because it's not on youtube yet.
Check it out on vimeo: