OK, I tend to use two phones on my Verizon service, swapping the SIM between them - the S3 and my Razr Maxx. Yeah, it's a question of what I'm in to mood to carry. However there are times when I also carry an iPod just to get some of the portable iOS apps I like. Since I can swap the SIM the Maxx and S3 are more or less interchangeable. Can I do something similar with the iPhone? My iPhone4 didn't take a SIM, so I have no idea how I'd manage that. Am I just out of luck?