I ordered mine from AT&T as an upgrade to an existing Gen 1 I phone for home delivery via Fed EX. Should just plug and play....Right?
Anyway, I was suffering from the same activation woes that seemed to plague many on these forums. I called AT&T and Apple and both told me I just needed to be patient. Nothing I did worked, Sim Reset, Air plane mode, off and on... Nothing. After many hours of trying to be patient I finally decided to visit a local AT&T store. I took the entire contents of the package as delivered up to the store and spoke with a very helpful AT&T associate (I know that sounds like an Oxymoron but in my case it was true). As she was trying to help me trouble shoot she started to discuss replacing the SIM and then discovered I was still configured in the system on the old Edge network. Then it dawned on her. She asked if I had activated the phone SIM by going to the AT&T activation site that was sent with my phone? Ahh yeah you have everything that was delivered with my phone... please show me where it told me I needed to go to an AT&T Web site. Anyway with a few clicks on a web site that I apparently had access to do from the comfort of my house I was up and running. I was like, It would have been real nice if the phone support people could have informed me of their own upgrade web site. It was never going to work until I hit that site.
Anyway, I walked out of there a lot happier and I also picked up another 3GS phone for my wife while I was at it..... Hey maybe that was their plan all along to get me back in the store!!! Oh now I feel used. lol
(Sorry - Activated the phone SIM should probably read: Upgraded the Phone SIM. The site was specifically for upgrading from 1 SIM to the New one on a current AT&T phone line. I think that may be why a lot of folks were able to just activate by switching to their old SIM from an Iphone 3G. I don't think the same switch out would work with a Gen 1 Phone Edge SIM card.)