Last thursday I was at a planning meeting at which a bunch of technology from different companies came through in a pinch.
We were meeting in a conference room, but were also meeting with two remote people, one from the eastern U.S. and one from out of the country. We hadn't done much pre-arrangement, but needed to get the meeting going in a hurry.
First of all, I found out I could AIM them through Office Communicator. I just typed in UserName@aol.com, and bam! They asked "is this a new username?" I never figured out what my screenname actually is when I use Communicator.
Okay, so over IM, we agreed to try Skype. So I downloaded it... I was a bit worried about whether it would work on Windows 7 Beta build 7000, but it worked fine.
Another participant had brought a webcam, so I plugged it in via USB, and immediately Windows recognized the camera, and Skype figured out how to use its mic and video feed. Finally, I plugged in the conference room's AV system into the audio out slot, I called both of the remote participants, and voila!
The only hitch was that Skype seems not to support video mode with a more-than-two-way connection. Perhaps they do that out of consideration for bandwidth.