The Night Circus were started during National Novel Writing Month (or NaNoWriMo).
I am taking part in this year's event, and I hope I can keep it up. If you'd like to participate, too, just go to www.nanowrimo.org to sign up. Once you create an account, you can receive help planning your novel, join local groups of authors who are also writing, and receive online encouragement from published authors.
If you aren't quite up to that challenge yet, you can try other writing incentives. For example, WriteOrDie.com offers three levels of "encouragement" for writing. The first level gives you gentle reminders to write. The second level plays an annoying sound until you write. The third level, which is hilarious, will delete all of your writing if you don't keep up with your goals.
So make a very early New Year's resolution: Write!