Jim, been thinking about this, but to be honest, I already have something set up that would certainly do the job....
http://www.corvettetopsites.com/
Not only does it allow people to show off their websites, but it also serves well as a hit counter for them.
There are some scripts around to allow people to post links to their sites and categorize them based on interests. I've got one running in another field right now...
http://www.faunalinks.com/wsnlinks/index.php
As for allocating a forum category for that purpose, not sure how useful everyone would find that to be.
Thanks.