fic_rush is a monthly, multi-fandom fanfiction marathon. You spend as much as you can of a 48 hour period writing fic, and tell everyone how you're doing by posting in our hourly check-in threads. You can chat, encourage each other, set goals for yourself...and then get back to writing fic. It's a great way to push past writer's block or just connect with other authors.
Round 1, which is sci-fi themed, is this weekend, starting Friday night/Saturday morning at midnight GMT.
eta: Since months later this post is still near the top of the comm, I thought I'd add this note for anyone who wanders in here and sees this ad. fic_rush is an ongoing, monthly thing. So if it sounds cool, don't let the date of this post scare you off!