Drkfusion: That is just part of sleep, you woke up before your body turned off a certain chemical that is sent to the muscles durring sleep.
I am no expert but here is what I understand of it: In your sleep your body repairs itself, most things must be relaxed so they can be repaired. Durring sleep your body produces a chemical (probbly not the correct term...), this paralyzes while you are asleep.
Sometimes you will wake up and it will take a few minutes before you can move, I have had this happen to me a number of times. At first it was scary but I looked it up, now I understand it is normal and it dosen't bother me much anymore :)
My first experance with it was a bit worse then yours. I could'nt move which freaked me out, but I managed to open my eyes. For the minute or so that I could'nt move I could see something out of the corner of my eye and I thought it was someone that had broken into my house and injected me with something and thats why I could'nt move. I kept trying to reach for the shotgun I have in the corner of my room beside my bed but I could'nt move, eventally I broke free, grabed the gun, but when I brought the barrel to where the person was standing it was gone.
I know now that my mind played a trick on me, and there was never anyone there, but at the time the thought 'someone is trying to kill me' was racing in my mind, and that minute felt like it lasted forever.
edit- googled it for ya...
http://watarts.uwaterloo.ca/~acheyne/S_P2.html
Your body can play tricks on you :), the mind is even worse...we are just starting to understand the power of our own minds.