Hey, I was shaking my iPhone for Facebook up and down and noticed a rattling noise coming from the top left of the phone, by the camera. I wasn't sure if the rattle noise is suppose to be their or not so I tried my friend's white 16GB iPhone 3gs and noticed their was no noise in his. I then went to the apple store and noticed that the noise was also present on the display model iPhones. Does anyone know if the noise is normal or not? and whether I should take it to the Apple Store for a replacement?