I tried last year and made it to about 11,000 words before school and work got in the way. That story involved a life size chess set that came to life, searching for its lost queen. I was drowning in deep water until I killed a character then all the pieces started falling into place. By that time the month was almost over so I didn't continue.
I did write one novel, in May 2007, with my friend L. We followed the same guidelines used during this month-long contest. I ended up with 50,044 words and three murders, one attempted murder and a 20 year old murder solved. I felt as proud of that novel as I did when I earned my master's degree.
I was talking with L and G today about this year's contest. L said she couldn't find her notebook where she had written some notes for a future story she was thinking about working on this year. She thought it was in a blue notebook, but she's been unable to find it. I told her I didn't want to hear another word from her about how organization will set you free. She just grinned.
When I wrote the story for May 2007, I started with the idea and went from there. I had no idea who my characters were or how the story would turn out. In the end, the killer ended up being someone I was not expecting. I will now have to rewrite some scenes to add new information because this character didn't show up until I was writing that last scene.