3G usage

I asked the same thing, but no one yet has mentioned a way to do this.
Sounds like a good idea for an app, doesn't it ?

Forget the app, just go to Settings, General, Usage. It will display up and down usage.

This seems to need to be reset manually when the new period starts, so keep an eye out for that.

The on-device management system only tracks usage for the 250 plan. There is no need to track usage for the unlimited plan.

Get the 250 plan and monitor your usage. You can always upgrade your plan if you need more.

Here is AT&T's Data Plan fact sheet: http://www.att.com/Common/aboutus/files/pdf/emerging_devices/iPad_factsheet.pdf

I have the unlimited plan and if I go to Settings, General, Usage, it shows my usage to date. This is not part of the AT&T management system.

If you get the 250 plan and then switch to the unlimited plan, you will be starting a new 30 day plan (not paying the difference in dollars to finish your original 30 days). So it's not an upgrade. It's new.

I started out with the 250 plan and without doing much, the 250 didn't last a day.

I, too, am interested in tracking my data usage with the unlimited plan. I started out with the 250mb plan and then AT&T changed plans. I felt I needed more time to monitor my 3G usage before deciding on the plan best suited to my needs. I needed to take the unlimited plan while still available to me. The 2g plan will probably be sufficient but I feel I need more time. Not being able to track usage on the unlimited plan is not going to help with the decision.