In this vein, you might find this Robert X. Cringely article interesting: http://www.pbs.org/cringely/pulpit/2007/pulpit_20070831_0028...

Money quote:

Video conferencing has been around for a couple decades, but telepresence is different from that. You can see the entire other side of the conference table, for example, and the people who are sitting across from you appear to be life sized. They can see you and you can see them. When another person speaks to you they can look you in the eye. Body language and emotions are easy to detect and the sound of each participant seems to come from his or her direction. You can watch the people who aren’t talking to see if they are even paying attention. It really is tele-PRESENCE and the fact that you are looking in a video screen is forgotten after a minute or two.

They even make sure to decorate all the rooms used in the system identically with the same lighting so as not to ruin the effect

HP Halo rooms do exactly that. They are an arced desk in a room, with 3 giant screens in front of you. Exact same furniture, exact same lighting, exact same environment.

And it's amazing how well it all works.

Not the same.

"Depending on the number of screens used, these high-definition video teleconferencing systems that deliver life-size images of the participants used to cost $500,000 or more per room."

Life-size video chat!

+ XGA LCD Projector ($800)