Have you heard of Liquipel? They claim that they can waterproof your iPhone (iPhone 4, iPhone 4S, iPhone 3GS and a few Android Phones) so that the device can be submerged in water without a case and still work (without even triggering the water sensor). Pretty amazing. We are going to be putting them to the test and getting one of our iPhones treated with Liquipel and we will report back on how well it works.
Checkout the Liquipel site for videos and more info