Right now I currently have event presenters simply email me Powerpoints and Word docs they used in their presentations. Then I create a static html page listing all of the sessions and workshops during the event by session # and then list the related document downloads.
Would I would really like to see is a photo gallery where users could upload their photos from a specific event. I believe some photo-sharing websites allow this, and Facebook certainly does for their event invitations, but post-event photo galleries would be a really nice way for people to share their experiences.