How about creating a new field in the threads database like 'ThreadGenre' and keeping track of the genre of each thread. The person posting the thread could select a genre that best suits the topic. Then when browsing threads the viewer could select a genre and filter the thread list based on genre. Another table will have to be made in the database for genre and of course the proper HTML, server side coding, and SQL will need to be developed.
I think it will allow people to focus only on certain types of threads if they wish. For example....Today I feel like only talking politics or redskins or entertainment or whatever genre exists in the db.
Just a thought...I think it would be cool enhancement for some members.