I consider myself a dyed-in-the-wool night owl.
My aunt tells stories about how when I was a toddler she would put my brother to bed and I would pretend to go to sleep too, but actually once he was asleep I would get up and my aunt and I would stay up late drawing and playing games together. Hm, maybe that's why I've always associated night-time with fun! :-)
Currently I work mostly in the evenings (teaching) and I go to bed sometime around 3am and get up around 11am, sometimes an hour later, sometimes an hour earlier.
BUT I am going to try to put aside my skepticism and give the early-riser thing a try starting the week after next-- I'm going to a different time zone where my 11am is their 5am, so voila-- instant early riser! The challenge will be maintaining that for the entirety of my stay (about three months).
I've already ordered an alarm clock that has a pillow-vibrating feature to shake you awake, I figure I can use that without the sound and not wake everyone else up at the ungodly hour of 5am.

I want to hit the gym first thing, and work on starting my own freelance business.
I may start a thread on this forum of the "30-day experiment" variety...we'll see!