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Tried mine at about 11 pm last night (missed delivery and the UPS customer center was a nightmare). Took two attempts, with a total time of about 5 minutes.
 
I wound up having to go to the Apple Store, where they confirmed I had a bad SIM card. Got a new one, and had instant activation.

Too bad I wasted all that time on the phone with them.
 
Defective AT&T SIM

I just got an email from Apple saying my iPhone shipped with a defective SIM and they will sending me a new SIM via overnight shipping. No wonder I had to use the old SIM to get the phone to work. I wonder how widespread this problem is.
 
So glad I checked this thread. Thank you to whoever provided the phone number. I waited just about three hours after trying the online activation. Calling the phone number activated it in less than a minute.
 
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