Random idea: How about a mobile multi-player game where any player can grab and throw digital balls found around them and the goal is to get them in specific spots? They could be found using GPS/augmented reality and you could shoot them using your phone's sensors by swinging the phone or a gun/canon app with specified settings for example.
1. They detach comments from comment threads (to hide them?)
2. They boost some stories so that they remain on the home page for a longer time
3. They also remove some posts from the front page... (because they are duplicates, not "quality" content, etc...)
I could probably come up with more examples, but I'm sure that you get the idea...