I had always wondered what the phenomenon I experienced was and recently figured out it was sleep paralysis when I read an article about it on cnn.com.
For me, right as I am about to fall asleep - think of someone sitting and the head finally tilts down and their eyes close - right as that happens it's like I jar myslef and half wake back up, now unable to move. I can see around my room for the most part, for instance in college I could make out my roommate at his desk. This is always acompanied by sort of hallucinations where I am being attacked by shadows or dark figures that are rushing at me or flying at me. Ocassionally I will feel like I am floating or moving around. I think that I generally wake up pretty quickly, although I guess I can't be sure, but that's how it seems.
This started for me when I was 16, Im 24 now. It used to happen most nights but now it is pretty infrequent. It is definetely trigered by sleeping weird hours, being tired, and maybe drinking/partying. In general if it happens it will be on a Sunday, as I have been up late going out Friday and Saturday night and disrupted by regular work week sleep schedule.
It was rather terrifying at first but I actually got pretty used to it. As stupid as this sounds, I would find my self talking [censored] to the shadows, if you will, once I realized that they couldn't hurt me. I will say that it is amazing how sometimes I felt like I could actually experience a physical sensation from these things though. One time it was even somewhat pleasurable. But in general they just rush at me and I wake up.
I don't really have any advice for you. Just my experience. One thing the article did say was that if you sleep on your back it is 5 times as likely to happen. Link below:
http://www.cnn.com/2007/LIVING/perso...per/index.html