Question: Selling iphone 3g to get some cash for the new upgrade. The new iphone I believe takes a micro-sim? My current 3g uses a regular sim. When I sell mine to my friend, can I leave my old sim in there? Does it hold any account information I should worry about? I should be getting a new sim with new phone with same number? I believe the iphone 3g needs a sim in it for it to work. He plans on using it as just an ipod touch and not getting service on it (wifi only). So basically, do I have to worry about the sim? or should I just keep it? Thanks.