I'll be going to Italy in a few weeks and was wondering what the best way to have cell service over there would be, since I currently have an iPhone 4 on Verizon, and that's not compatible with the networks over there. I still have my iPhone 3Gs that I had with AT&T prior to upgrading and switching to Verizon. What I want to know is if I can just rent a SIM card from some carrier over there and plop it in my iPhone 3Gs and it just work. Or would I need to do some sort of unlocking via a jailbreak and stuff first since it wasn't unlocked by AT&T prior to moving to Verizon?