Got offered an unlocked 32gb iPhone 4 the other day for decent money so decided to buy it just to sell on as I already have 1. However, after I bought it I remembered the problem I encountered with the last unlocked iPhone and wondered if I would encounter the same problems here. My friend had iPhone 3GS on o2 that he was selling so I said I would have bought it if it would take my orange sim. Day or 2 later he called me up and told me he had got o2 to unlock it, I tried my sim iit and it worked so I bought it. Couple months later I went for iPhone 4 and sold 3GS to another friend who was on o2 but wouldn't accept his sim card. Turns out when u2 had unlocked it so it could take my orange sim either they or orange then locked it down to orange network and to change it back to accept o2 would cost £15. Is the iPhone 4 going to cause the same problems? Did I just hit those problems because it was originally purchased on contract from o2? Or am I likely to run into them again here? There is a vodafone sim card with the phone but a little afraid to connect to iTunes and set up incase it locks on Vodafone. If this fone was bought from the shop as an unconnected handset can it be changed to different networks without the £15 unlock fee?