Works fine :)
Here's how I set up tethering using only pre-installed Ubuntu 9.10 software (i.e. no Blueman):
- Set up your Mobile Broadband connection in NetworkManager
- Install this (Bluetooth DUN) from Extras
- Set up a Bluetooth connection using the Bluetooth Applet in GNOME
- Note the BT address of your N900 (e.g. by using "hcitool scan")
After this setup is done, here's how you can tether your computer with the N900:
- Open a terminal and type "sudo rfcomm connect 0
" - Wait for "Connected /dev/rfcomm0 to
on channel 1" - Click the NetworkManager applet and select the Mobile Broadband connection

Very nice! This should be included in the Maemo platform , worked better then installing the whole PC Suite and trying to get connected...