At work I use Skype all the time to talk to co-workers to minimise disruption (and also to gossip :p), but I do still sometimes go to people's desks when I can't be bothered to type out what I need help with.

At House! I used the IM in Warcraft to talk to Pete, whose PC was downstairs in the lounge. We can't get away with that in Spontaneity, since our PCs are next to each other ;)