I just posted at the CUNY Academic Commons Development Blog about a plugin that I wrote for BuddyPress. Check it out if you are interested: http://dev.commons.gc.cuny.edu/2009/05/16/new-plugin-custom-profile-filters-for-buddypress/

The Custom Profile Filters for BuddyPress by Boone Gorges, unless otherwise expressly stated, is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.