I do this through sprint and when it works, its great!
I've had issues with sprints software....over 2 laptops and 2 evdo phones....i'd say about %65 of the time their software doesn't recognize that the phone is connected. A reboot of the phone and/or device doesnt help.
I currently have a blackberry 7130e with them and its a dream device....and when the evdo modem feature works, its a life saver!