I had the Pre for a couple days (I ended up returning it) but in just 48 hours I burned through 150 MB of data using Sprint's EVDO. That really shocked me because much of the time I used the phone I was at home on my WiFi router, so I can see why carriers would be scared about overloading their networks...
Oh, and to put things in perspective, my normal EVDO usage is less than 50 MB a month (unless I tether).
