Heh...I couldn't even send an SMS over EDGE/GSM. If you have a 3G phone that supports ATT's 3G bands (850/1900MHz) then it'll usually prioritize 3G over GSM, so if it finds a 3G tower, it'll use that and fallback on GSM only if it needs to. And yes, if you're in a call, it'll hand off from 3G...