DrupalCon Chicago was a joint effort between GVS and Palantir.net. GVS built the site with COD, and many improvements that were made to the DrupalCon site were contributed back to COD.
For example, there's a tabbed interface to separate the curated sessions from the community-proposed sessions, which get voted on by the community. Administrators get an extra views of the content to help see sessions that need publishing, their ratings, and more.
Visitors can filter the lists of sessions by Track, Skill level and keywords. On the session page itself, they can add the session to their personal schedule.