Yes, there is such a thing! Just go to
http://www.nanowrimo.org/ and it'll have all the info about it. It's a contest that takes place every November where you must try and write an entire novel. Don't worry about editing and don't go back and reread. That's for after. Just sit down and write. You can post exerpts of the story and give a word count. The goal is a 175 page (50,000 word) novel in that 30 day period. A high challenge but one I was willing to accept last year. I got about 5000 words and snippets of a story. Not this time.
The site has all the info. It's a lot of fun and a great way to challenge yourself. You can start thinking of ideas now but you can't officially start writing til November 1. The site will also be locked down this week so they can prep for October 1 registration but I got an e-mail about it today and wanted to fill everyone in.
I have every intention of trying again and I hope you'll give it a shot, too.