Only a design, the Gravisa Lamp is a super green LED floor lamp claimed to make use of gravity to generate power for hundreds of years. The lamp is completely free of any plug-in electricity by making use of a slow fall of a mass to spin a rotor which generates electricity to power 10 built-in high output LEDs. To turn on the lamp, you have to turn it over to move the weights from the bottom to the top of the lamp (sorta like an hourglass). Slowly it will fall to generate electricity to power the LEDs.
Cray Moulton, a Virginia tech student, designed and won first place of the Greener Gadget award. He claims the lamp could be used for up to 200 years at 8 hours a day.