Ok so I was half-awake today. On my bed, with my eyes open, just thinking, in a daze. Then I felt a "function" in my mind I didn't feel before. I uhh used it and then this is were I got scared. My eyes started to close slowly. I tried to move my leg and couldn't. My thoughts were getting screwed up. I was freaking out. I couldn't move, could't speak, and fought to keep my eyes open. I could only move my eye-lids, see, and hear. Finally I was able to move and got straight up. I am still trying to figure out if that really happened. It really scared me.

Are you sure you were awake already? I get a very similar feeling if I have multiple dreams (a dream within a dream). That always freaks me out.
I'm quite sure I woke up so I try to do something, but I can't - and then I wake up again - still not able to move. This keeps repeating itself until I finally really wake up - I'm usually all wet from sweat at that point.

I knew I was awake, because I could hear my mother and father having a conversation about the party they were going to in the next room.

I think that's happened to me in the past, you are right, it is damn scary, my body wouldn't respond and I could only just move my eyes. I can't remember what I did to stop it, I either jolted myself into action and was able to regain control or I just closed my eyes. I'm still not sure if it was a dream or not, it was far more vivid than anything I've ever dreamt.

I have experienced the same as Sebatianos explained.
It usually happens when you are just been sleeping and waking up.
Normally you don't dream at this stage so intensely but it can happen.
it is possible you heard your parents talk while still dreaming (much like you can hear an alarmclock going off while you're still dreaming)

usually these dreams occur when an alarmclock goes off and you turn it off in your dream and it continues again and again.

I've felt that too. About 2 or 3 times in my life. Scary as heck. Scared the crap out of me. did I mention how scary that was. Of course, I have had a dream where I was either drinking something or felt something, and when I woke up, I had wet the bed or still felt what I had felt in the dream, whether it was a pain or whatever. Those things are wierd.

I experienced that too, maybe it's like that for people in coma?

I had some of this too. It is usual for me, when something should wake me up, I just dream something about it continue sleeping. Like the alarmclock. I had an experience: I was sleeping, then the alarmclock started beeping. My dream was about some space ships and I dream that some emergency signal gone off. I done something on the dashboard and it was over(my alarmclock stops after 1 minute of beepeing). It was fun :D Dream the reality in your dream :D

It's not a dream I think. When I was in my teens I used to experience the same phenomena; always when I was about to go to sleep.

It's as if you're in a different state of conciousness. I remember that it felt sort of like you're about to fall down on your back (if you're lying on your back). I was always afraid I would let go and allow myself to fall, because I didn't know what would happen then. I suspected that if I 'fell' I would never wake up again...

Then I read about it in a popular science magazine (Dutch, KIJK). Turned out one of their staff also had experienced this phenomena. But she was not afraid to let herself 'fall' and she ended up having fantastic visions.

Well, I don't know. Perhaps I'm too scared of the unknown but whenever I was about to 'fall,' I always fought it with all my inner strength. Trying to get my eyes open. Now that I'm a bit older I've never had that experience since.

Perhaps it's just a panic reaction and we should try to relax and just see what happens.

I've read some about this.
It's due to the body still beeing in "sleep"-mode and everything but the autonome system is practicly paralyzed. You do however have controle over your eyes since they are controled seperatly.

This funktion is there to prevent the body for harm during sleep, where dreams else would be actualy carried out by the person who's having them.
To some extent, ppl who sleepwalks have "mallfunction" in this paralyze-system.

I'll try to see if i can dig up an artchilce or two and post here, on the subject.

Anyway, it's perfectly normal, but unusual. Most commonly triggerd by sudden waking up during a REM-face of the sleep. (REM = Rapid eye movement, btw)

Sidenote: many ppl claiming to be abducted by aliens experince the same thing, imho it's a combination of sleep-paralazys and dreaming/imagenation.