Here's a pretty clever way to keep the iPhone 4 partially protected without using a full case: id America's Cushi ($12). Rather than a traditional flat sticker, Cushi is a cushioned soft foam pad that adheres to the glass back of the device without leaving any residue. It is also compatible with Apple's iPhone 4 Bumpers, so you can assemble both side and back protection. Three different designs are available, each with a unique 3-D texture. Included…
