Mophie has introduced the Juice Pack air case for the iPhone 4. Just like the juice pack air case for the iPod touch, the iPhone 4 case combines a protective case with backup battery power. Mophie says the air case will double the iPhone 4’s battery life. The case is light-weight and low-profile, with a soft-touch exterior and a 2-tone metallic look. All ports and controls are exposed for easy use, and you can charge and sync the iPhone 4 while it’s in the case. There’s a battery display on the bottom. The Juice Pack air even acts as a “virtual speaker box, redirecting sound from the bottom of the iPhone 4 to the front, resulting in a richer, fuller sound quality.” The Juice Pack air for iPhone 4 is $79.95 at Mophie.