National Novel Writing Month, or "NaNoWriMo." A yearly event held every November in which people try to bang out a 50,000 word novel in the course of a month.
Honestly, every year I think "Oh cool, I should do this" and every year I've got way too much to deal with to ever consider it. Why don't they do it in February when Winter grips the Northern Hemisphere and there's nothing else to do (unless you're in ski country)?