Great menu system - Tag based filters?

[garyion]

We came across this forum
http://www.gameslurp.com/gaming-forums.php
which has a really cool top menu which appears to filter tags to allow users to easliy search content in the same forum. By default all the threads appear. When you select "WII Forums" it filters just those posts tagged "WII Forums". When you post it gives up predefined options to tag (at least i think its a tag) your thread in one or more forums e.g.("WII Forums"). On the main forum this allows you thread to appear in the "All" and "WII Forums"

My question - is it possbile to do this for a subforum, for example our site is divided in 100's of locations around the country. Could we have a subforum for each location with a set predefined tags in the "post thread" just for that subforum.

e.g say we have a subforum PARIS in an overall site about France. I post a thread tagged "wine" I just want that tag filterable by a menu on the Paris subforum only and not forum wide.

If its not tagged is it something else?

feedback would be great!