Urine! That's right folks, the NoPoPo (!!!) batteries from Japan can be recharged using your own bodily fluid (or any other that's primarily water). When the charge dies in these things you use that little baster that it comes with to charge them back up. Allegedly the magnesium and carbon react in a magical way to produce more energy. No word on price or how you're supposed to get urine into the little squeeze tube, but I imagine not easily. Just don't get lazy and try to cut out that step by peeing directly in your electronics. You'll end up not charging anything but your personals. ZAP!
Rechargable Batteries Run On What? [therawfeed]