A lot of these instances that people have mentioned could be classified as out of body experiences/astral travel/lucid dreaming. There are threads on these subjects:
http://www.tfproject.org/tfp/showthr...threadid=25686
http://www.tfproject.org/tfp/showthr...threadid=22817
http://www.tfproject.org/tfp/showthr...threadid=35906
http://www.tfproject.org/tfp/showthr...threadid=29316
Something like this happened to me only a few days ago. I was having a dream, then I found myself floating on my bed with only one arm resting on the bed, then the next thing I know I was floating upside down with my head resting on the bed. I then woke up and promptly started to fall asleep again. I had some really clear visions, then there was a really intense, rapid buzzing in my ears and my hands were really tingly. It felt like someone had jolted me with electricity. Thats when I sat bolt upright, totally spun out.