The entire conference could have been done over the web with VO-IP conferencing. Co-op World has had many virtual conferences. Podcasting, Business Expos, Dog Expo ... Just my 2 cents.
Virtual Worlds 2007 - Virtual Worlds Conference - produced by Virtual Worlds Management - read the entire article
Excerpt: Virtual Worlds Fall Conference and Expo takes place October 10-11, 2007 at the San Jose Convention Center. The event follows the highly successful Virtual Worlds Spring Conference which took place in New York in March.