Windows Messenger

I'd been looking at that little thing that pops up every now and then in the lower right hand corner of the screen in the CR and tells me when the Greenwood Reference Dept. had logged on. It's instant messaging. So, Pam and I have been IM'ing each other this morning (as it is realllllllly slow). But I can see actually using it instead of the phone to let each other know when a "question" is headed their way. "Word processor open? Sending someone over." "Sending over a reference question on lemurs - not enough info here." That sort of thing. Or, "I brought in cookies," which is what I actually sent.
Who else has this? GRD is the only thing I've ever seen logging on. I remember reading about IM'ing in Bridget Jones's Diary, which means it's been around for ages, at least internally. I don't use it on the internet at home. Does anyone do that? I mean, if I want to talk to someone in real time, I'll talk to them. I'll get the cordless phone and wander around the house, getting a snack, etc.
Does anyone here do the internet phone? They use the internet video-phone at Piedmont Tec, but other than that I don't know anyone who has it.