New iPhone user (US, AT&T). Do we need to do the occasional tower update like was called for with Verizon? Used to have to occasionally dial "228 SEND", and phone would go into programming mode. Then, by pushing "2", it would update my roaming capability, and I believe it would teach the phone about "new" towers in the area. The last part might not be totally or even partially correct, but that's what Verizon reps explained. I know that I could not access the just installed 3G tower until I did the "228 send" programming.