With some help I managed to get search engine friendly urls on my existing phpbb2. It involved .htaccess, renaming files without an extension and forcing php and a bunch of path to graphic changes (some like smilies and avatars still need to be done).
vBulletin would most certainly have had my business if SE friendly urls came as standard. Maybe there is something to be learned there for Vbulletin :-/
Fine product though, and had I not already installed phpbb then I would have bought it anyway.
Good luck Drk. It will be worth the faffing about I'm sure. Getting found on SE's seems to very undervalued here, but I can tell you your registrations will rise a lot after a couple of months I'm sure.