There are now two new pulldowns on your profile page: one for categories and one for boards/forums. You can see them in action on your POSTS and FAVORITES tabs:

http://boards.hellobee.com/profile/

You can use these pulldowns to filter your list of posts (and thread started), as well as your list of favorites.

Thanks to LindsayinNY and T.H.O.U. for requesting these features!