Gravity Lamp —
About two weeks ago it was announced
that a U.S. grad student, Clay Moulton, won second place in a "Greener Gadgets Conference" competition for inventing a floor lamp powered by gravity.
was that a person would place a weight (about ten pounds) at the top of a four-foot column. Over the course of the next four hours, the weight would descend down the column, causing a rotor to spin that would produce a gentle light (about the strength of a 40 watt bulb).