MIT students James Graham and Thaddeus Jusczyk won first place with the "Crowd Farm," a proposal to produce electricity through stomping feet at the Holcim Foundation Sustainable Construction competition in Japan.
The idea is that the floor would contain a sub-floor made up of several blocks that would slightly depress when someone stepped on it. The slippage of the blocks against one another as people walked would then generate power through the principle of the dynamo, a device that converts the motion energy into that of an electric current.
A single step doesn't pack a lot of punch--it would light up a 60-watt bulb for a second or so. But thousands of commuters could light up signs. (The image here shows the inner workings of a crowd farm.)
The two also created a stool that generates power to light LEDs and installed it in a train station in Torino, Italy.
Others, such as Zhong Lin Wang at Georgia Tech, are trying to generate ambient electricity by converting mechanical energy into electricity via piezoelectric principles or temperature differentials.