Synchronous software service for free use. Easier than elluminate or Breeze, seems quite simple to use. No conversion needed to use PPT or PDF. free. Give it a try!
Ellumiate session with the second half focusing on the ways Birmingham Public Schools have used wikis throughout the district. Links to dozens of wiki ideas are mentioned.
http://ignite.wikis.birmingham.k12.mi.us/Wikispaces