With friends in every time zone, your cell never stops blowin’ up. It’s tough to find a phone with enough endurance to meet that kind of demand. Now, you can rely on a battery instead. The Mophie Juice Pack Air ($60.00) houses a rechargeable battery inside an ultra-thin iPhone4 case. The extra “juice” doubles your talking, surfing, and music listening time while keeping your phone protected. Your Russian dolls and British birds will all appreciate that.