Please bear with the lengthy post, I just want everyone to know the specifics of the problem I'm facing right now before responding. I bought a used damaged iPhone 4 last week with the intention of replacing the LCD screen to find out that there were many other problems with the phone. I brought it to the Apple Store and found out that I had 1 day left of the original warranty. They exchanged the iPhone for a new one right then and there for free but because I don't use AT&T, they couldn't activate my iPhone in the store. I right now have a 3GS iPhone that I am using with T-Mobile and I had planned on jailbreaking and unlocking the iPhone 4 and switching back and forth with my iPhone 4 and 3GS. (the 3GS is a 32gb and the iPhone 4 is only a 16gb) Unfortunately I haven't been able to get a T-Mobile Micro SIM card yet because until the iPhone 4 is unlocked, I'd have to use my 3GS with an adapter with I ordered, but hasn't come in yet. (and you cannot have more than one SIM card assigned to a phone number at a time) Here's the problem.... Right now if I turn on my iPhone 4, I get the "Connect to iTunes" logo and the option to make an emergency call. When I connect the iPhone to iTunes, I get a message saying "We're sorry, we are unable to continue with your activation at this time". I'm unable to get my iPhone 4 to the point where I can jailbreak it and unlock it to use a T-Mobile SIM card. The question is, can I activate a brand new iPhone 4 with a T-Mobile SIM card or can I use someone else's active AT&T SIM card just to activate the iPhone so I can get it to the point where I can jailbreak and unlock it and use it with T-Mobile?? If I use someone else's AT&T SIM card just to activate my phone, would my phone end up being associated with someone else's AT&T account? If anyone has had a similar issue, what were you able to do to get past this issue??