Here's the story. I already have an iPhone 4 with an activated SIM Card (under 3 Network in UK). My mum ordered an iPhone 4 as well and hers just arrived today. Her one is also on the same network as mine, but the SIM card is not yet activated and the iPhone is not yet synced. My question is: Will it be safe if we swap iPhones (using an already activated SIM on a brand new one and vice versa)? The reason I want to do this is because my mum's iPhone is for jailbreaking purposes (new one running at 4.0 whilst mine is running at 4.2.) Thanks.