I actually can sleep with my eyes open and have unconcious episodes where people believe I'm awake. The eyes open usually occurs when I am very tired but trying to stay awake. I really freaked a roommate out one time. He came home from the bars and I was sitting on the couch asleep. He said he talked to me for like 10 minutes before he realized I was asleep.
The unconcious episodes occur when I'm really tired and someone tries to wake me up. This usually is just me answering questions or talking on the phone. In the morning I remember none of it and it really ticks people off sometimes. Once when I was younger, I was told to go to bed and I was found 2 hours later asleep standing beside my bed. Didn't remember any of it in the morning.
My fiance has screaming episodes every once in awhile. Man, that took some getting used to. First time, I almost jumped out of my skin. Now it's sort of fun, since she remembers nothing. If I walk in the room when she's asleep she will sit up and scream and jerk all around. Very funny stuff. The worst is when she has conversations in her sleep. She will start what I believe to be a normal conversation and I will begin to talk to her. About 2 or 3 sentences in it becomes very apparent that she is just ranting nonsense. Like,
Her: "Did you take the dog out?"
Me: "yes."
Her: where did you go?
Me: I didn't go anywhere, what do you mean?
Her: The house is running under the couch fence..
Me: WTF!!!!!