Storybot

Storybot is an IRC chatbot I once wrote that allowed people to collaboratively create a short story. Every user in a channel would write a few lines of a story. Once every user had written a line, they would vote on the line which they thought fitted nicely in the story. The winning line would then be accepted as 'canon' for the story. It's slightly hard to explain, but was a lot of fun.

Source (PHP code, designed to run on Linux via php-cli) can be found here.