Last month, I got a $1500 Cingular bill that was inaccurate. I was charged for both my unlimited data plan for my Treo and by the bit. Since I do screen reloads on espn.com scoreboards about once every 45 seconds on the weekends, all that data added up! It was an obvious mistake, but it took 5-7 business days for someone to research it and get back to me and 3-5 more days to fix it. I would have been screwed if I was on one of those "autopay" plans.