I've been monitoring my data traffic through the Verizon wireless site occasionally and noted that after about three weeks I had used somewhere in the neighborhood of 1.9 Gig of traffic. Was talking to a couple of other Droid users and they noted usage for 1 - 2 weeks at about 1/10 of that.
Checked the detail of the traffic and found that a VERY healthy amount of the traffic has been happening between 12:00 AM and 6:00 AM when, as far as I know, my Droid is plugged into the wall charger getting juice for the upcoming day.
The apps in use seem pretty innocuous to me. It varies slightly from day to day, but include email of course, corporate calendar, browser, market, twidroid, weatherbug, and a handful like the settings app, etc. The most probable guilty party is slacker radio, but in general I have it shut down.
Has anyone else been wondering about these numbers and is there a good app out there to monitor network usage and the source of that usage?