The Universal Wrist Charger is not, tragically, a motion-powered portable battery chargers which tops up its battery from the movements of your wrist. That would make my job way too easy, and would pretty much write its own rather juvenile jokes.
Instead, the Universal Wrist Charger is portable battery chargers lithium-ion battery pack with a mini-USB output and 1,500mAh capacity. The wrist-mounting is merely for convenience, but the simple addition of the wrist strap appears to make this a whole lot better than the usual re-juicer. The use-case that the seller ThinkGeek pushes is that of charging a Nintendo DS as you play, but any handheld device that can be charged with 5.5v will work, from cellphones to cameras to media-players. To this end, the portable battery chargers comes bundled with nine chargers, from the PSP and the DSi to the iPhone and both Nokia adapters.
At $35, it is similarly-priced to other device-specific solutions. That is looks a little like the teleport bracelets from 1970s kitsch-fi Brit series Blake’s 7 doesn’t hurt, either.