If you thought the American Express card in your wallet was the perfect tool for solving all of life's little emergencies, think again. This wallet-friendly backup battery can charge your iOS devices or serve as an emergency sync cable.

With just a 400mAh battery tucked inside its 7mm thick case, the card's not going to be able to charge more than one device before needing a recharge of its own. But the fact that it doubles as an ultra-compact sync cable more than makes up for that limitation. And for just $12 it even includes an LED flashlight for emergencies that don't involve uploading one last Instagram photo. [USBFever via Gear Diary]