[Macha]

> I don't install non-work IM programs on my desktops anymore because I found that an 'online' status typically denoted to people that I'm available to talk.

With the exception of Facebook Chat, that is the purpose of the Online status. There's (busy/your client's name for it) for "I'm here, but may not be able to reply". And offline for when you're actually not available. If it wasn't for Skype's terrible offline messaging implementation, I'd have said that 90% of the time offline or busy implies you should probably close the IM client.

(Facebook is different because afaict, there's no way to manually put it into the away state, it just does it if you haven't interacted with Facebook in a while)