Anyone who's ever broken it down on the dance floor knows how draining a dance club can be. Two engineers from Holland came up with an innovative to put the energy to use: the Sustainable Dance Floor. The concept, which was launched in 2005, puts springs beneath floors and gears that convert the vertical movement of the bouncing floor to rotational movement. The mechanical energy is then converted to electrical energy, most of which is used to power the LED lights in the floors. The Sustainable Dance Floor by Energy Floors is the world's first energy-generating floor. Coming soon to a club near you, perhaps?