This Mota Extended-Battery Case for iPhone 4 and 4S, listed at $69.95, is now $29 at Groupon Goods. Plus, shipping and returns are free. The best price we could find anywhere else is $46. It features phone protection combined with an extended battery that adds up to 6 hours of additional web browsing time, 10 extra hours of video time, 300 hours of standby time, and more. It comes in several colors as well. Sales tax is charged in some states.