National Novel Writing Month

From the site:

National Novel Writing Month is a fun, seat-of-your-pants approach to novel writing. Participants begin writing November 1. The goal is to write a 175-page (50,000-word) novel by midnight, November 30.

Valuing enthusiasm and perseverance over painstaking craft, NaNoWriMo is a novel-writing program for everyone who has thought fleetingly about writing a novel but has been scared away by the time and effort involved.

Because of the limited writing window, the ONLY thing that matters in NaNoWriMo is output. It's all about quantity, not quality. The kamikaze approach forces you to lower your expectations, take risks, and write on the fly.

Make no mistake: You will be writing a lot of crap. And that's a good thing. By forcing yourself to write so intensely, you are giving yourself permission to make mistakes. To forgo the endless tweaking and editing and just create. To build without tearing down.

Pretty cool!