Yes, the user name and password is same for all cingular customer. It is amazing if you ask Cingular customer support to confirm the password and user name and Cingular will tell you to buy a $59 data connect kit.
http://www.cingular.com/business/data_connect
Please don't by data connect kit for $59. If you got T68i and Bluetooth CF for Axim or Laptop then you just need the set up I described earlier.
So Cingular got great technology but the customer service really not traine to help cusotmer. Lots of green people in tech support.
Please make sure that you use all capital when entering the password and user name.