Spare Battery Cellphone Strap: There When You Need It

The only thing I don't like about thin phones is the perpetually run-down battery pack. We've seen fuel cell, solar, and USB battery packs for your phone. But this remote cell charger is guaranteed to present when you need it, by virtue of its strap. And I'd like it a lot more if it came with a plug for phones sold in the US.

Cellphone Battery Strap
[Tokyo Mango]