wireless_cn2002 via eBay offers this 2,200mAh Portable Backup Battery in 12 colors, model no. 389H069, for $5.99 with free shipping. That's $2 below our mention of a similar item from three weeks ago and the lowest total price we've seen for a 2,200mAh backup battery. (It's also a current price low by $2.) It charges and provides backup power to USB input-compatible devices, including iPhone, iPod, and most other current smartphones.