Though they're just shells -- half-cases that snap onto your iPhone 4 to protect only the back, parts of the sides, top, and bottom -- United SGP's Genuine Leather Grips ($32) differentiate themselves once again with the quality of their leather, which looks nicer than the inexpensive appliques normally placed on plastic shells. Pictured here are two Infinity Black versions, one with embossing and the other without, each packaged with a crystal clear…
