Tanga offers the Duracell Powerhouse USB / mini-USB Device Charger
, model no. PPS3US0001, for $9.99
for shipping. (To find it, click "Second Chance Deals" under the "Save" tab at the top. It's in the sixth row down.) That's tied with yesterday's mention mention as the lowest total price we could find by $2. It features a 2000 mAh external battery and can power two devices at once (via USB and mini-USB) with up to 60 hours of backup power.