Any chance of a discussion  forum?

Preferably a vBulletin if poss :)

Could quite easily add a general discussion forum to this - the advantage as far as I'm concerned being that it wouldn't cost anything. It might be worth looking at third party products or spending some more time improving what we have if it starts getting busier ....I see vBulletin costs a bit - do you think it has significant advantages over a free forum platform like PHPBB?

I would say yes. VB is especially good and it does attract people to use it more frequently. I'm surprised there isn't a free open source version as good as VB but if they're making money then i suppose they can afford to continually make it better and better.

Maybe just try PHPbb to begin with but put it in the main nav so people know its there. It'll be important that the Forum profile is tied directly into the website user account. I think you can do with with both!?

Yes it would definitely need to be tied to the existing user database - no one is going to want to have 2 logins.