I'm using the Belkin Acrylic Case, I've read bad reviews about it like scratches, but mine's perfectly fine, been goin 2 weeks. *I might have jinxed it* It makes it look like a mini cinema display and or a G4 tower. The charge dock is useless however with the case on, which kind of sucks because I think the sound/chirp the iPhone makes, when you plug it in with the dock, goes hand in hand with it.
With the Belkin Acrylic Case for the iPhone:
It's not just a phone, not just an iPod, not just a web browser, but also a beltbuckle.