While the battery life on the iPhone 4 isn’t bad in comparison to most smartphones, we still find ourselves running low on a daily basis thanks to Web browsing, photo-taking, and that pesky Angry Birds game. Your iPhone can do just about anything: Let you communicate with friends, help you choose a restaurant, give you directions, or tell you if the price on that gadget is reasonable. When your phone dies in the middle of the day you realize just how often you use it to help with daily tasks. The Mophie Juice Pack Reserve ($35) aims to solve that problem with a keychain-sized battery boost that you can have on-hand at all times.
The Juice Pack Reserve is small enough to attach to your keychain, which makes it extremely convenient, and will give your iPhone about a quarter of its full charge if you run out of juice. The gadget has an integrated 30-pin dock, USB port, and a special high-output battery cell that will charge up to twice as fast as traditional 500mAh batteries. Invisible LED lights let you track your iPhone’s charging progress at a glance. At this reasonable price and with such a compact design, we’ll be putting this on our key ring as soon as it’s released. No more bailing on your friends because your iPhone died and you’re incapable of finding directions sans-smartphone app. The Juice Pack Reserve also works with iPods, for those of you who still have them.