Is it possible to take an AT&T sim out of a friends iPhone and get it past the emergency screen (then put it back and have it still work)? My 3GS does not like the sim from another AT&T phone and seems to want a straight up iPhone sim.
I have been able to use a friends AT&T SIM card (he has a prepaid standard SIM card), what I did was hooked the phone up to iTunes and put the SIM card in it, iTunes did a little sync and the emergency screen went away (I didn't do anything in iTunes, it still had the "Let's Get Started screen up), put the prepaid SIM back into the friends phone and no problems.