You can spend upwards of $80 on a fat extended battery for your iPhone. Then you’ll have to worry about having it constantly strapped to the phone – and when it runs out of power you’ll have extra dead weight to carry attached to your phone. Instead consider this ultra-portable sync and charger cable for iPhone and iPod. This device works on both old and new school model iPhones as well as the new Nanos, Touch and iPod Classic. Store the cable attached to your keyring – when you’re in need of a battery charge find a computer with an open USB port. It’s admittedly a bit less convenient than a battery but at $70 – $90 cheaper it may be a good emergency power solution.

Sync and Charger Cable for iPhone/iPod