OK I know some people still are confused on this so I am doing this for the benifit for everyone. There is no speculation here. This is all based on official Apple and AT&T info. This is the SIM Tray... As you can see from my hard labor in MS Paint the tray is located between the headphone jack and the standby button. There is a small hole that you insert a paperclip or similar object in to release the tray. Now...some people seem to be thrown off on the whole "preinstalled" text. All this means is that the card was put into the tray when the iPhone was made. It is a normal removable SIM that you can use in any other GSM phone. The following was taken directly from the AT&T Training Guide posted on Boy Genius today... Hopefully this clears everything up once and for all. If not then Friday will tell you the same thing I just did.