I don't know much about anything, but what I do know is that I like polls. Just as users submit new stories, users could also make up poll questions which would be available for the masses to vote on. For instance:
Of course, only heavily voted on polls would make it to the front page. But it could be an interesting tool to find out how people feel about a certain topic.
Similarly, quizzes would also be an interesting feature offering multiple choices, rather than just a simple 'yea' or 'nay'. I'll save you the heartache of another paint image by leaving this one up to your imagination.