Whitelist for Adium?

In his recent IDEO video, I thought I heard Merlin say that Adium has an easy way for you to filter who sees you online. I think I inserted wishful thinking into what I heard because I can’t find what I’m looking for. Maybe you can point me in the right direction.

What I’d ideally like is a whitelist. I have dozens of contacts on my buddy list. When I’m trying to get work done, I don’t want to be available to everyone in order to decrease interruptions. That said, there are two or three contacts I would still like to be available to, like my girlfriend or business partner. Ideally I could tell Adium to set my presence as invsible to everyone except those in a certain group. The only thing I can find is per-user presence settings (i.e. “Always appear offline to Username”).

Any thoughts on how I can accomplish this? Thanks!