I started a challenge on my blog:
http://brynnstein2.wordpress.com/author/brynnstein2/ Each week I'll post a prompt and have people write a short scene (or longer if so desired) to answer it. It's not fandom related per se, though you could certainly take the prompt and write about the characters in the fandom of your choice. The prompts aren't innately slash, though they'll deal with two men. Several Dreamspinner authors have already said they're interested in taking part. It should be fun.