I'm just about to purchase a case for my iphone case that can sustain getting wet. I know there's a lot of cases that claim to be waterproof. I'm looking for something that is small enough to carry everyday and can survive a dunk in a lake. I'm looking for firsthand reviews from someone who has used one. I've looked at Lifeproof and the Griffin Survivor. I like the Lifeproof but it costs half the price of the phone ($100) however; it is very form fitting and small.
West Marine sells clear dry bags meant for small electronics. Touchpads work through the plastic, plus, if you seal it with some air inside, I assume it will float.
I have an Aquapac. As Jon said, mine appears to be water tight, but I have yet to test it on the water. This year I'll take the iPhone I replaced with a newer version. The phone doesn't work, but the other apps do (race timer and GPS).