Apple was having a bit of a bad day yesterday, completely shutting down their iPhone activation service until further notice. There were numerous reports of people trying to activate brand new iPhones, and they were bumping up against an error message informing them that iPhone activations were "not available at that time." Apple is telling people to hold off until tomorrow, but hasn’t given any specific information regarding the shut down. Calls to AT&T revealed that the problem is, indeed, on the Apple/iTunes side of things, and that a fix could come at any time. When the dust settles, it will be interesting to see just what caused the outage, and what steps AT&T/Apple takes to fix the problem.