register your account on Cingular.com You will be able to check your bill online, but it does not update till the next day or sometimes 2 days. That means data/calls/text messaging will show on your bill, but a couple days after the usage. Then it will reflect on your cingular.com bill. Hope this helps
Another option that some phones have (both Nokias that I've owned have had it) is a text message counter. I reset the counter on the 1st day of each billing cycle, and this gives me a more accurate count of my text usage in case of delayed reporting by Cingular.
=^..^= There must be a happy medium somewhere between being totally informed and blissfully unaware.