There are several battery packs available for the iPhone, all with their strengths and weaknesses. Some devices are "generic" and are meant to be used to charge any USB device, but these require one to carry the appropriate USB charge cable. Others are "emergency power" only and are very small and dangle precariously at the bottom of the iPhone. Most people don't want to carry a bunch of extra gadgets and would prefer an integrated battery solution. NitroX agrees and have released their iConn Plus iPhone case with integrated battery power.