No case for me. I've been using the iPhone 4 case-free for 27 months and there's nothing but some minor scratches on the back that can only be seen in the right lighting. I think so long as a person keeps their iPhone in a front pocket all to itself no case is required. My feeling is that having the world's thinnest smart phone but cramming it in a big fat case kind of defeats the purpose. Likewise for iPads.