Interesting. I sometimes have trouble waking up in a dark room as well, but I've found that increasing the volume of the alarm clock and the distance I have to travel to get to it normally solves that problem.
My first job out of college was a start-up in the financial industry; strolling in at 11am was highly looked down upon, and so ended my budding career as a finance whore.
Added: One of my responsibilities was to make sure my brothers got up in time for school. I can tell you from experience, that if you have someone to help, ice water is a great motivator to get out of bed.
He was mad, as he pulled a double shift because of that, but hey...beauty sleep :D