Finally, an IM service that allows differentiated availablity:
In InterComm, a user organizes the people in his IM list by different groups, based on the work relationship he has with them..."Everything in InterComm is built and organized around groups," Englar said.
This architecture allows a user, for example, to only make himself available via the InterComm IM system to some groups and to appear offline to other groups at any given point, based on his work priorities at the time. "I think this feature is very valuable because a key issue that has made IM not as appealing in the workplace is that it's interruption-driven," Radicati's Hung said.
I doubt that you can really define your relationships to the proper level of granularity, but it's certainly a step in the right direction. It would also be nice if you could keep internal traffic off the internet, but they are working on that.