There's only a few dozen dozen out there to choose from. What's your price range? What features are you looking for? Do you want the experience of doing it yourself or do you mind buying one off the net?
There is full code for an ASP Messageboard over at ASP101.com. It's worth checking out, to serve as a starting point for your own Messageboard:<BR><BR>http://www.asp101.com/resources/aspforum_revisions.asp