Oh yeah, addendum to my previous post: Try thinking of something really fucking awesome. And when i say awesome, i mean riding on a giant bear fighting the legions of hell with ludicrous guns blazing AND DESTROYING HELL IN THE PROCESS. Now picture yourself in that place, and try your damnedest not to yell "OH YEAH". This tactic has helped me fall asleep many times. Not necessarily the aforementioned thought, but y'know. If you get an equally awesome dream, then it's a double bonus.