Advertising different IM statuses to different groups of people

I think Robert Scoble has a point in saying that it would be cool if you could be able to advertise different IM statuses for different groups of people (I’m at work, so tell those guys in the office, but not my drinking pals. Oh, and my family can always see me). Then again, he also misses the point I suspect — why do you folk have so many people you don’t want to talk to in your IM lists? If you want to talk to random people you have no relationship with, why not use IRC, chat rooms, forums? I’m weirded out by this trend for letting random people Skype you for the same reason. I have a phone because it’s convenient to me — if I don’t want to talk to you, I’ll not answer. I’ll listen to the voice mail later, and reply if it’s needed.