Microsoft Roundtable
Many of our conference rooms at work now have Microsoft Roundtable devices. It's a speakerphone and 360 degree web cam. You plug it into your laptop for video conferences and the video feed automatically switches to show whoever is talking.
I blogged about this last summer, but I recently used one in a video conference for the first time. In theory it's a simple idea although I suspect it took a lot of work to develop. Unfortunately they are $3650 so I won't be getting one any time soon. (Also I have no idea what I'd use it for.) If you do a lot of video chats at work, this is something to look into. It provides a very nice experience for the person/people on the other end of the chat.
You can find more information and some screenshots of what it looks like inside Live Meeting on microsoft.com.