Perhaps the most energy in emerging teaching/learning collaboration technologies today is being put into creating virtual learning environments. These virtual worlds are populated with avatars. Avatars are those animated characters that can take almost any shape or form and - in many virtual worlds - can talk and interact with other avatars.
Second Life and other virtual environments enable a kind of immersion in learning and engagement. See how the avatars interact directly with one another.
The New Media Consortium is among the leaders in the use of Second Life for collaborations. An introduction to their islands is linked to the title of this posting.
UIS is currently collaborating with the Illinois Department of Public Health in the Brothers and Sisters United Against AIDS / HIV project. http://webcast.uis.edu/impatica/danto2/VidToursUIS.html
A great look ahead in virtual learning environments:http://connect.educause.edu/Library/EDUCAUSE+Review/LookingtotheFutureHigherE/47222
An incomplete list of colleges and universities who are using SL:http://www.simteach.com/wiki/index.php?title=Institutions_and_Organizations_in_SL#UNIVERSITIES.2C_COLLEGES_.26_SCHOOLS
Second Life is not the only virtual environment:http://www.virtualworldsreview.com/
Google has gotten into the virtual environment game:http://www.lively.com/popular