I just got my kid an iphone (and I don't even have one!). Anyhow, she has the only smartphone on our plan (AT&T) so I got the 300mb data plan. She is in school all day and uses wi-fi at home. So, she will use "data" when in the car or at a friend's house.

How can we check her data usage throughout the billing cycle? I asked the salesman at the store and he gave me a very loosy goosy answer -- basically, that they will send you warnings when you are close to an overage but they are outdated as soon as you get them.

Overages are $20/mo so I'd like to avoid them!