I can say that it is within my experience that this is all true. I have left my body and viewed myself on two occasions within the last year. The first time was while tripping and the other was while on no drugs at all (except caffeine).
While I tripping I was sitting in the backseat of my friends car being driven to a friends house where I could sleep. I was having a casual conversation and during a pause in the conversation... for what could be described as... my vision blacked out and saw myself from a fixed angle in another time and space. I was looking directly at my own face and when my facial expressions shift in the real world, the facial expressions of my face in this other time and space shifted to match them. I smiled in amusement and saw my face in the alternate time and space smile in amusement too, then I looked away in embarrasment and my face in the alternate time and space looked away in embarrasment too! What I mean by alternate time and space is, I was in the back seat of a car at night, but the me I saw was not in the back seat of a car and it was clearly day time, although I am unsure where I was. I then shook it off and looked over to my friend in the back seat of the car and tried to explain to him what I was experiencing, but it didn't really seem to come out right, so I said something like, "Ok, I'm going back now." And then I went back to viewing myself from the same fixed angle and in the same alternate time and space. I also found that I could go back and forth from in the back of the car, to this alternate time and space. This effect lasted for like...5-20 minutes... its hard to gauge.
The second time I left my body this year was after staying up all night writing a paper. I was exhausted but kept pushing myself so I could finish. I had drank a lot of coffee to help stay up. Then around the time I would be in my deep stages of REM I went down to the Cafeteria (it was 7:00 AM, and the cafeteria had just opened) to eat breakfast. Everything was normal except when I was carrying my cereal on a tray over to a table I left my body and watched myself continue to walk towards the table. I wasn't so nervous about viewing myself from outside my body as I was nervous that I would lose my balance and fall over, but that never happened. I shook off the effects, sat down, and looked around for a friend to tell about what had just happened... hell I considered telling a stranger... but that might give me a one way ticket to months of sedation in the psych ward at the local hosptital ;) or at least cause that person to get up and move to the other side of the cafeteria :P Anyhoo, I went on to finish the unremarkable paper and still went to class that day. As far as I can figure, this is what happened; during dreams (REM) our brains stop holding back this stuff that makes us "hallucinate," (or something like that) and because I was awake when I was absolutely not supposed to be (that is when I am in my deepest REM state), those thingies that hold back hallucinations were weakened and let a hallucination come out and that is why I saw myself from the outside.