The Survivor + Catalyst case for iPhone 5 from Griffin is waterproof to 3 meters and has an IP68 rating; you can even take photos and videos underwater.  Griffin consulted the U.S. Department of Defense's Mil-Std 810G regulations when designing the case, so it's proof against 6-foot drops onto cement, wind-blown rain, and vibrations.  It has a polycarbonate exterior with nylon controls covers.  The silicone gasket PET screen cover keep the outside out, and the interior TPE bumpers absorb shocks.  The Survivor + Catalyst is a utilitarian case that doesn't have to look utilitarian.
The Gadgeteer , Protect your iPhone 5 with Griffin's Survivor + Catalyst waterproof case, Protect your iPhone 5 with Griffin's Survivor + Catalyst waterproof case
