i.Sound Portable Power Max 8,000 mAh for iPod, iPad, iPad2, iPhone, Droid, and Blackberry for $49.75

Anyone who's ever had the battery die in their cell phone, MP3 player, camera, or other electronic device knows what a pain it can be (and that it always seems to happen at the most innoportune moment). iSound's Portable Power is perfect for avoiding these annoyances: an ultra-portable backup battery that will charge multiple devices at once, without the need for an AC outlet or multiple backup batteries. Never run out of power for your mobile devices. Portable Power for Your Mobile Devices 8000 mAh Battery An 8,000 mAh Lithium-Polymer battery provides up to 240 hours of power, so you can talk more, listen to more music, and view videos longer.