So basically, over at Twisting The Hellmouth right now there's a round robin fic going based on reality altering Agents of fanfiction. Somehow, against all odds, a plot started developing and currently Mistress Jinni (head of the COA) has been kidnapped by Dr Evil, Lucius Malfoy and Missy. With a cast of thousands and written by anyone who can get their hands on it, to say it's sprawling is an understatement.
But it's also incredibly funny in places. Anyone can add in a chapter at any time, featuring anyone they want, so come on in!
Now, where did I leave that evil!clone!Sam Wincester?