I thought it would be a good idea to have a backup for my new 3Gs so I bought a really nice, pristine 1st gen iphone off ebay only to find out that I can't just simply swap my sim card back and forth between the two phones. I wanted to try out the 1st gen to see how good/bad it was compared to the 3Gs but when I put the sim card in, the phone wouldn't work. It (itunes) took me to the screen used to activate the phone. I went to the ATT store and they informed me that the 1st gen operates on a different data plan and that while it is possible to "switch" to the 1st gen plan, I would have to call them EACH time I switched the sim card back and forth. I didn't ask but I don't suspect they would let me switch back and forth too often without getting annoyed? Anyone have any suggestions on how I can use the 1st gen by just swapping the sim card or did I just buy a REALLY nice Ipod/Itouch?