NaNoWriMo. I've been a participant (and a completer) a handful of times in the past, and I'm here to encourage you to GO FOR IT if you can. You never know what greatness might occur; what jewels in the rough; what bezoars in the poo, or whichever metaphor you prefer.
Don't believe me? Well, two of my three PUBLISHED novels started during NaNoWriMo. I wouldn't necessarily describe myself as either a panster or a plotter, but the evidence seems to tip me into the former category, doesn't it? When you let the words flow, sometimes that's what you need to find your voice and loosen your imagination.
So. No excuses (unless you're like me and have enough work this month for at least two months' worth of stress)--grab your computer and get going!