Do a little search for the Razr and phonecontrol as I know it's talked about a good bit already. I have the v551 and I think both these motorollas only support 1 bluetooth connection at a time, so it's kind of a "workaround" how phonecontrol works with it. Took a little tweaking but I got it to work with mine, but what it does it connect to your phone (bluetooth) over a serial bluetooth connection to control the phone and let you know when you have the call, if you take the call on the screen then it drops that bluetooth connection and reconnects to the phone over a handsfree/audio gateway connection so that audio is routed through the computer.
It works, but at least for me it was never 100% stable. Sometimes it wouldn't reconnect to the phone, or sometimes I couldn't hang up from the screen, etc... If I go back to using it I'll just use it control the phone and just use the phone itself or a wired headset.
I've got the same medianet plan it works fine with dialing up to get on the internet, not very fast but enough to check simple sites out or check email or something. Only thing is that since the phone only does 1 bluetooth connection at a time then phonecontrol will have to disconnect in order for you to dialup through it.