If you're in the market for a portable battery pack/charger, the Godfather of them all just went on sale at Amazon: the ridiculously massive 16,000mAh i.Sound Power Max.
The Power Max has five full-size USB ports for powering/charging basically any device you can throw at it, be it an Android phone or tablet, iPad, Blackberry, or anything else with a maximum requirement of 2.4 Amps and can charge over USB. Another cool use is overnight-charging of multiple devices while only using one outlet. Just plug the Power Max into the wall, then charge all of your devices at once through it. Very convenient for travel.
While the 16,000mAh version is currently going for around $70, if it's just too big for you, there's also an 8,000mAh version that will set you back $45.
Hit the link below to buy!