Actually this idea has come up a lot in threads lately, and I've been thinking of adding features of this type. E.g. to help people find jobs.
What features do users want?
What features do users want?
Business networking site XING also has user's list what they are currently looking for and offering
Beyond that, why not just let the users define their own boxes? Though I'm not really sure what multiple boxes can do that one box can't.