Apparently November is grow a mustache month or something. Not something I'll ever do, and I'll tell you why.
I once had a dream--one of those dreams that begins with waking up, except you're not really awake, you just think you are--went into the bathroom, looked in the mirror, and I had a mustache. I looked like such a total douchebag that the shock woke me up (for real). I resolved then and there never to grow facial hair.
Also I don't think I could grow one in 30 days. At the rate that I sprout whiskers, it would probably take me at least 6 months.
On the other hand, the hair on my head grows so fast, if I went for 6 months without cutting it, I would look like the guy in the back.