With earlier iPhone models, external battery packs and battery cases like the Mophie Juice Pack Air became very popular, due to the original iPhone's shorter battery life. With the iPhone 4, we're not seeing quite the battery life issues that we did with the earlier models, but for those who need to be away from a recharging power source for a while, battery cases are still an excellent solution.
Exogear has recently released the Exolife rechargeable battery case for iPhone 4 ($89.95), with a built-in 1500 mAh Lithium-Ion Polymer battery that's sure to keep your i
