pecunium

Boin Boing points to this article from Rueters about a backpack which uses the same idea behind self-winding watches to run a small generator.

So far so good.

Their backpack design converts mechanical energy from up-and-down movement of the backpack's cargo to electricity during normal walking.

Fueled by a snack, hikers can put the spring in their steps to good use, the researchers write in Friday's issue of the journal Science.

The backpack is deliberately designed to shake around a bit. The up-and-down movement of the backpack's cargo compartment against the frame of the pack turns a gear connected to a generator.

Ok, I can see that, and as they say, food has a lot of energy (food is measured in calories, but there are two kinds of calorie, heat calories [n a standard unit of heat equal to the amount of heat required to raise one gram of water one degree Celsius], and food calories, which are kilo-calories, i.e. 1,000 heat calories),and they say they can get 7 Watts out of it.

This is more than enough electricity to simultaneously power an MP3 music player, a personal digital assistant, night vision goggles, a handheld global positioning satellite navigation device, and a mobile telephone.

All one has to do is is walk (wait for it) Humping along just under 85 pounds (38 kg) of weight in the backpack

Yep, for the effort of plopping 85lbs. on your back you can listen to your iPod and and run your GPS.

I've carried an extra 80lbs, on occaision. That wasn't just the pack, that was rifle, pro-mask, boots, uniform and water.

Lets just say it was done under duress, and will only happen again under similar duress. I'm a small guy, 80lbs is about 2/3rds my body weight, it ain't good for my knees, my back or my rate of travel to carry that much. Thirty pounds, OK but that's my camera rig, a book, and my pennywhistle. I'm not gonna hump even that, just to charge my cell-phone, for that I can get the hamster to spin the wheel

Eighty-five pounds. Sheesh.