How about a Quizbot?
It would be an add-on feature to an integrated IRC chatroom - the bot 'resides' in there, and poses questions which the chatroom participants then try to defeat each other in answering the fastest.
There could be a temporary leaderboard for the current round of trivia, and a permanent one (which could be reset on a regular basis if desired) to show overall rank.
This is an idea a friend of mine came up with but never actioned as his career keeps him too busy to devote time to such a project.