I'm an early adopter, and got my first cell phone more than a decade ago, so I've had my experience with cell phone service. Over the years I've had Sprint, Verizon, AT&T, T-Mobile and now Cingular and I have to say that to say that of all of them Cingular is by far the worst. I know that all of them suck at some point, but Cingular's idea of customer service is somewhere below that of Abu Graib prison guards.
When I first signed up to get my wonderful HP iPAQ 6515 ready to accept email, they only signed me up for a limited data transfer account. So they then proceeded to bill me $500 for voice calls. THEN, because they didn' t bother to let me know that I would be charged extra if I went over a certain amount of data transfer, I was charged another $600 for dowloading email spam. After we sorted that out, they cancelled my account and charged me $150 for the priviledge! I called to get that reversed and the email still didn't work. After three months and about two hours on the phone, we may have finally gotten the phone working. I wish HP would go back to selling T-mobile phones!