I just purchased two iPhone 3G's today and now have to decide what to do with my two old iPhone's. One was in perfect working order, the other destroyed by being dropped in water. My question: I plan to sell the working phone but want to know how I can completely clear it so that it's safe to sell. The second one, I can't even turn it on and don't see a purpose of selling it for parts, especially if anyone figures out how to get it to work there is data on it. How can I safely destroy the iPhone so that no one is able to get it and recover data?