Here's a clever one - the iCoat bubble case for iPad and iPhone. While normal bubble wrap wouldn't last long, this is a tough, light and tear-resistant case.
Made by Ozaki, the jelly cases are available in clear or translucent black, and cover all the sides of the device. It allows access to all controls and ports without removing the case. The design also comes with 'invisible' screen protector. Available from HMV, audioout.co.uk & ebuyer.com