Got a Lifeproof case yesterday after seeing adds in Backpacker. Expensive, but fully waterproof AND light AND thin AND can use everything including the camera. Can even shoot underwater video (to depth of 6 feet). Just what I've been looking for. I left it as a test at bottom of a bucket of water overnight and nary a drop. It's expensive, but worth a look if you take your iPhone everywhere on trail like I'm now doing.