Sometimes you need people to believe you are offline when you are not, just to get work done. You want the option to IM them, but you want to be able to not reply and, if you don't want to reply, have them think that you are offline rather than being rude. This is what Yahoo Messenger's "Invisible" status is for. IntelliJ users need this occasionally to get work done without being IM'd to death. Please add this feature!