OK, word of pre warning, don't click on the first link here. It's Protonmedia
-- one of those very slick company "solution" websites where a little video host talks to you like you were 5 years old. Yuck ;-)
The company makes integrated Web 2.0 tools for busnesses. Chat, IM, whiteboards, social networks, virtual worlds, etc.
The interesting thing is how they could be used for education and why this might be more appropriate than Second Life. There is a good explanation here on Tom Crawford's blog.