Want turn on your desk lamp? Flip a switch! Right?
Man, that is such pre-energy-crisis thinking! How about, instead, you lift a 50 lb brass weight a couple feet up. The lead weight then, slowly, falls back down toward your desk, producing enough energy to squeeze a few hundred lumens (as much as a 40 watt incandescent) over your workspace for the next few hours.
That, in a nutshell, is the idea behind the Gravia. Actually, the concept that won runner-up at the Greener Gadgets Conference actually is a floor lamp, and it requires quite a bit more lifting (about six feet) to power it for four hours.
Still, I rather like the idea. It's good to have an idea of where energy comes from, and it's even cooler to know that, if your light is out, you need to do more than just flip a switch. Reports swarming the internet that the lamp will stay lit for for 200 years (thanks for all the misleading headlines guys!) are unfortunately erroneous. In fact, the lamp produces only four hours of light per lift, but the LEDs, according to the designers, will last for 200 years of use without needing to be replaced.
Now if only someone could guarantee me that these aren't just going to take a nose-dive into basements to collect dust like a crank-powered Billy the Big Mouth Bass...then I'll be satisfied. As it is, I can see people getting pretty tired of lifting a 50-lb weight six feet in the air every four hours...