For years, GelaSkins has made decorative stickers for pretty much every consumer electronics device imaginable, including iPads, iPhones, and iPods. HardCase ($35) represents the first time the company has branched out to something different; rather than a sticker, it’s a polycarbonate shell for the iPhone 4 or 4S. While we’re not enthusiastic about shells for the easily-damaged glass iPhones, the big selling point here is design. As with all of the…