Just got my iPhone 4, and it's great. Been trying lots of things out and came across an app that updated when shaking. When I shook the phone I could clearly hear something rattle inside. I kept shaking it to see if I could figure out what was loose checked all the buttons and didn't seem to be them. Then I noticed after a little shaking it said "NO SIM" so I thought this must be it. I took the sim card out and shook again and it still rattled so it doesn't seem to be the sim. Everything seems to be working fine. I set up a Genius appointment for Tuesday to see if they know what it is if it will be an issue. Anyone else seen this?