I successfully did NaNoWriMo this year, writing over 50,000 words between November 1st and November 30th.
I've done NaNo once before, in 2004, for a specific set of reasons. I wasn't sure if it was wise to commit this year, or if I'd get much out of it. As it turned out, it was a good challenge and showed how possible it is to make time for writing if you have the motivation. I have always known that I need deadlines, no matter how arbitrary, to function, and this has proved it.
It is very tempting to rest on my laurels for December, but I am trying to maintain the momentum of writing at least a little every day. And putting off the evil moment when I have to try and edit 50,000 words of nonsense.