An event activity wall can help to create engagement between users at your event. If you want to lead the discussion you could restrict new posts to admin, sponsors or speakers whilst still allowing delegates to comment and engage.
By default users are anonymous at the event, unless they choose to be visible as an active delegate. In doing so, they can send/receive onsite messages, see who's viewing their profile, post articles and comments and even befriend/follow other users. Your event can become its own social network.
Email email@example.com if you'd like a login or demo.