The simple solution to all of this is to eliminate overages and do throttling, like T-Mobile. I'd rather have 200MB with throttling down to Edge speeds than having the headache of worrying if I'm about to hit my cap and be charged an overage. It makes for better marketing as well because of less worry. Just use your phone and if you want to go back to 3G speed the rest of the month, pay to renew the data plan. I'll join the class action because I don't like unpleasant surprises in my bill.