I'm giving serious thought to participating in NaNoWriMo this year, because I actually remembered it before November 15th this time. The question is mostly what to write.
I have tons of stories already started, but one of the requirements is that you start from scratch. I'm leaning towards writing something set in my failed D&D setting. I have background notes and NPCs that could be converted easily into main characters, which I suppose would count as outline/character profiles, which are allowed. Maybe it would even help me fix the setting so we could actually run a game in it sucessfully.
On the other hand, maybe I should start completely from scratch, or even work on a Dr. Who novel (I know somewhere in my bookmarks are the submission guidelines for Dr. Who novels - wouldn't it be cool if I actually managed to get one published?)
Regardless, it'll be a bit of a challenge for me - I don't normally write in chronological order.