Ok I just recently purchase an iphone 32gb 3gs. I had a first gen black jack that saved most of my numbers to the actual phone. When apple was activating my phone they added the few contact that were on my old sim card and put my new sim card back in. I'm planning on visiting Europe in the coming months and wanted to know if I could buy a pay as you go sim card there and actually get service for the phone while avoiding att roaming charges. Is the phone locked to only att sim cards or will my US phone except pay as you go sims?