Addendum: Ubuntu 9.10 Karmic with Blueman works _perfect_ with Bluetooth DUN/PAN because Network-Manager now supports these profiles! You set up your GPRS account (APN is important setting), select 'auto connect', then you configure Bluetooth via Blueman. Then you connect with Blueman to phone's N900 DUN (or, if you prefer, PAN) and Network-Manager will automagically enable PPP setup. You can even add another hook for VPN. So, no more need for wvdial. Even more perfect would be, if computer running Karmic would detect there is no WLAN, and then auto try Bluetooth, for example via BlueProximity.