Hi
We will be committing Beehive this week.
(I need someone to put it in CVS).
Beehive has whiteboard, chat, video conferencing and much more:
http://www.weg.ee.usyd.edu.au/projects/beehive/
You will need Macromedia's Flash communication server. But a development version can be downloaded for their site
In this project we have put a *lot* of focus on the best educational design practices. The systems uses IMS Learning Design to interact with the flash server, and uses the concept of educational design patterns to provide a wizard with many pre-built educational activities.
cheers
Rafael