It something we did with Big Brother 6 that worked well and that people wanted back for Big Brother 8. It just makes the place more organised.
Once people get use to it is easy to use.
If you read the board using the today's Big Brother post link:
http://www.thisisbigbrother.com/foru...ig_brother.php
you can see all the Big Brother posts without having to look at the sub-forums.