The Amphibian Waterproof Hard Case for iPhone 4 from Proporta is tested and guaranteed to be waterproof to 3 meters. You’ll be able to take photos underwater, and you can make and take calls while the phone is in the case. The system consists of a hard polycarbonate case that can be used alone and an outer silicone skin that protects against water, dirt, and sand. There’s a lanyard attachment point so you can wear it around your neck. The Amphibian Waterproof Hard Case for iPhone 4 is $37.95 at Proporta.