I bought an iPhone 3G but it didn't come with the original sim card to activate it. I want to update to 4.0b but want it to be unlocked too. The official carrier's site gives an unlock form to officially unlock your phone. I just want to ask: Can I use any O2 sim card or do I need one with the bolt-on as well? I don't have the original sim so do you think that any O2 sim would work as I am already unlocked via blackra1n. I doubt anyone could help me here, but any help would be greatly appreciated. Thank you.