In addition to a much-improved screen, faster processor, and a slimmer profile, the iPhone 4 also boasts the best battery life of all past iPhones. That said, there are bound to be times when you're caught out there with no access to a charger, power socket, or both. It's times like those when you're going to wish you had a case like the Mophie Juice Pack Air. Not only does it protect your phone in case you mistakenly drop it, but it also provides a crazy amount of extra power: six hours more talk time, five hours more Internet time, and 36 hours more audio playback time. Unlike other bulky mobile power packs, when you slide on the Juice Pack Air, your phone becomes only slightly thicker than the iPhone 3GS with protective case. So, you know, it'll still look cool.

Mophie iPhone 4 Juice Pack Air
Click Here to Buy It Now at Mophie, $80