eeek, happened to me for the first time last night. i was sleeping and was alarmed by a sound in the hallway right outside my room. the door was closed, and i kept hearing some movement, some rustling, it could have been my imagination, but i was hearing something. so my mind wakes up, but my body was stuck, i was scared sh!tless, i tried to open my mouth to say something, or get up to hide or something, but i couldnt move. i tried so hard to open my mouth to say something but couldnt do anything. i dont think ive been that scared for my life before, just because i thought someone was in my house and couldnt do anything aboot it. :}
A couple of weeks ago I had a dream that I was in a small room with one door leading out. This was about the end of the dream when I was in this room. Suddenly I heard some one pounding on the door like crazy! This was startling enough to make me realize that I was dreaming. After realzing this I was able to hear everything that was going on in my apartment and was able to feel my body lying down. At this point I was in such a panic because I was wondering if some one was actually pounding on my front door in the real outside world! All I could do was look around my dream environment and keep telling myself to wake up. Next, I began forcing my eyes to open so that I could wake. I finally got them open but when I looked around, the room was strange and I couldn’t figure out where I was. This is when it hit me that I was still dreaming! It took some real effort to physicaly open my eyes and phase back into consiousness. When I was sure that I wasn’t dreaming anymore I ran to the front door to look out the peep hole. No one was there and after a little bit of thinking I’ve decided that the pounding was actually in my dream.
What a wierd thing huh? Usually I’m trying like crazy to become lucid!
I have experienced sleep paralysis when I was younger, but not for a while now. I used to really struggle to move my arm or even to speak, but was quite unable to do so. The last time I had it, I decided to just relax and very quickly slipped back into a dream - this is my best way out of it so far. 
I have thought that I woke up in my sleep in the morning and heard ‘rustling’. I kept drifting in and out of a semi-conscious state. I was also convinced that someone was shaking the bed once, but there was no-one in the room when I woke up (quite scary). 
I had another similar experience when I thought I heard someone walking along the corridor and into the room, but again there was no-one there.
I think these two subjects are somehow related, but perhaps a more experienced/learned dreamer could elaborate on this?
I have had two expiriences of sleep paralysis over a period of two days. These two days I was very busy with schoolwork and woke up early to get it all done (awake for about 3 hours from 3 am to 6 am). Fortunately, during both the days, I still had another hour until I had to prepare for school. So, I went back to sleep. Without ever hearing of NILDs before, I managed to lucid dream both times. The first time I was excited because it was my first LD in a month or so, and only my 4th or 5th LD ever. I managed to go around and do things I wanted, but I realized I wasn’t able to remember what it was I wanted to do, so I decided to wake up. I tried very hard to move my body IRL, and I became concious instead. I was aware of my body’s posture and how I was laying there, but when I tried to move my hands and lift myself up to get out of bed, I couldn’t move. I was confounded at first, and hadn’t heard of SP before, so I just decided to wait about 5 seconds. I tried again and I was able to move easily. I thought about what had happened to me, and didn’t know the term “sleep paralysis” at the time so I couldn’t research it. But I managed to realize that my mind hadn’t allowed control of my body yet, because I was still “switching over” from dreaming. So I decided to try the same thing the next day and attempt to do a “hard un-paralysis” (can’t think of a better name), and force my body to become non-paralyzed. So, the next morning I LD again, and forced myself to wake up. Yet again in a state of paralysis, I was lying on my stomach with my hands to my sides and my arms at 90 degree angles and my head turned to the right. When I realized that I was paralyzed, I concentrated completely on pushing both my arms against the mattress, to push myself up. At first it was strange, I felt what has been called “electricity” on this forum surging through my upper body without any sort of pain. I felt as if I was expending large amounts of energy to do nothing, like a car attempting to get out of some sand and only moving the sand beneath the tires, and all of a sudden about 2 seconds after this I felt my muscles “catch”, and I pushed myself upwards, just as if the car had hit some sort of rock and propelled itself forward. This is the most accurate description I can give of this experience. Bleh! 
I had a really good idea I wanted to present, but I have rambled so long I forgot it… 
Oh well, if I remember, I will be sure to post it… 
kmcdonald: SP can be triggered by stress (eg. you said you had a lot of school work) and also lack of sleep). It also usually occurs when you sleep on your back, I think it is quite rare in other positions. And yes i know those kinds of feelings you described.
I went through a period of having the most extreme kind of SP where I would wake with my eyes open, seeing my real room, but seeing a dream presence that I had no reason to doubt was not real. Sometimes they would come and choke me, other times they would literally try and beat me to death, and being paralysed I could do nothing, the worst thing is that you can’t even scream.
Theres a very imformative page that includes (somewhere) possible reasons for SP from an evolutionary perspective, and a achance to participate in a study:
watarts.uwaterloo.ca/~acheyne/S_P.html
Also there’s a fascinating account of a LD/OBE experience:
watarts.uwaterloo.ca/~acheyne/sp … News1.html