Reverse your patterns. Only let yourself on the computer 8 a.m.-10 p.m. or something and don't allow yourself to have any sleep at that time. You'll be tired enough that you'll eventually do the night sleeping? Don't do anything "interesting" if you wake at night. Watch bad television at 2:30 a.m and keep your rooms too cool to be comfortable at night (I do that as I have trouble breathing when I sleep and cool air helps me). Then when you get up you'll prefer to be in a nice warm bed.

One thing that has been helping me lately is warm showers (yes, in the middle of the night too :-) Otherwise, I sometimes wake "hungry" and a little vanilla yogurt or a bagel or apple to chew on helps me then.

How about Advil or Tylenol PM? They're not drying like Benedryl (but don't make you quite as sleepy either). I take anything I want to help me sleep "early" (9:30-Midnight), go to bed and read for an hour or two until I'm sleepy enough to sleep.