PixelSkin HD for iPhone 4 - Black - Speck Products
.... Patterns and textures can turn “plain” into absolutely fabulous. PixelSkin HD has a shiny polished back with matte pixel overlay, creating an eye catching, sophisticated, and modern artful look. Light dances off the crisp, linear pattern of mathematical protection and perfection...My iPhone feels obese. I had grown accustomed to the slender, almost imperceptible, naked iPhone 4. The case is great, but it is still a case. It is also black, which was the only option. Were I spending my own money, I'd have bought a case that's harder to lose on an airplane seat.
I've seen Apple's bumpers recently, and I think they'd be fine too. They may even be more shock absorbent. This Speck case, however, doesn't interfere with older iPhone connectors and, of course, it does protect the back half of the phone and the camera lens. If you're going to use a case, you might as well protect the back of the phone.
Now that I have the case, I'll be more relaxed -- so I'm sure to drop the phone. (Same phenomena is said to occur with bicycle helmets).
I'll get used to the obscene bulk. One day ...
Update 9/25/10: It has a thin rubber segment that crosses above the connector slot. I think that will eventually stretch, catch on my pocket and break. One day ...