[eyepoker]

There are a lot of external batteries that when charged, will charge your phone. i have a Kensington battery which stores 1800mah... charges up my phone pretty quick - but at $60 i'll admit its not as handy as a $40+ extended battery thats a quick swap. Still, the Kensington is pretty slim and easily fits in a pocket and best of all its "transferable" - i can use it with whatever phone/device I buy in the future.