I don't have any sleep disorder and never really paid much attention to the duration of my sleep or the time to go to bed. After watching this video http://www.youtube.com/watch?v=8hAw1z8GdE8 ( Dr. William Dement on Healthy Sleep and Optimal Perfomance ) I'm going to bed at 11 and waking at 7 with excelent results.
I read a book by one of Dement's colleagues, James Maas: "Power Sleep".
I first heard Dement in pure-audio form on the Stanford iTunes. That talk was moderately better organized than the video version, although it would certainly be better if there was a punchier video available on such an important topic.