I did some research and read that the iPhone 4 had a rattle noise. Some people said that it was the on/off lock button and others said that it was the camera lens. I have noticed this noise with my new 4S. I hear it when I set it down on a table or when I tap on the back of the phone. I upgraded from a 3GS so I am a bit unfamiliar with what the i4 did. Does anybody else hear this rattle noise form their 4S? I'm thinking about making a appointment with the Genius Bar.