i say avoid cingular if you're anywhere in CA
it's crap here in the bay area, my friends bitch about it all the time. although it's not as bad once you start heading south or north, in LA it's impossible to get a signal out with the constant SYSTEM BUSY message. once you go north past davis it's impossible as well. i tried for 20 minutes to get a call out once to call home (cheaper long distance and during off peak hours) and finally gave up, it was rediculous.
i'm actually canceling my service to pacbell/cingular tomm to switch to the ATT Regional 120 plan. sure i get crap worth minutes, but the service is considerably better and i get free long distance and no roaming, all i need is 120 minutes. i seriously don't think you need more then that if you don't have a long distance relationship or anything, i mean we all have aim right ?