This is an important feature that was missing in the 3.0 release. The iPhone OS released on 09-09-09 now has a tracking meter in the usage page of the control panel. If you don’t have a large plan like I do, this can make your life easier and save you from sweating a bunch while connecting your precious device to a Windows PC that downloads sneaky large updates in the background.
Nice – if I could still use tethering with 3.1. So I’ll wait for reactions.