Aloha TEG,
Actually it was Cingular's signature service - IIRC, AT&T did not have rollover minutes until they acquired Cingular. It's actually more accurate to say that rollover minutes are NOW At&T's signature service
HawaiiMacAddict
You understand that the change from Cingular to AT&T was more of just a simple name change, not a buyout.
SBC changed their name to AT&T because of the brand recognition and owned 60% of Cingular. They started selling under the AT&T brand name before SBC bought BellSouth.
It's not like AT&T "bought" Cingular, it's just that SBC bought the rights to change the Cingular brand name to AT&T.