How many times have you been out and your phone dies? Carrying your charging cable just isn’t an option. They’re long, and just don’t fit anywhere in your pockets. Meet Prong PocketPlug ($70), a smartphone case that features a built-in wall charger for iPhone 4, iPhone 5, and Samsung Galaxy S III. It was an absolute lifesaver while down in Austin, TX for SXSW. Everywhere I found an outlet, I threw it in and charged it up.