Here is a fascinating documentary about dreams, "BBC Horizon: Why do we sleep?" I think it was made very recently because it contained a lot of new scientific information about sleep which I'd never heard before, such as that it turns out that we actually do dream in non-REM sleep as well as in REM sleep.
Near the end, a sleep researcher makes the comment that there is little difference between dreaming and our waking states in actuality--which is something Buddhist masters have said for a long time. Check it out.
Part 1
http://www.youtube.com/watch?v=qwroGbH1laY
Part 2
http://www.youtube.com/watch?v=0r1PUoG3 ... re=related
Part 3
http://www.youtube.com/watch?v=tPOMrfans90
Part 4
http://www.youtube.com/watch?v=pYDsCGcb ... re=related
Part 5
http://www.youtube.com/watch?v=Dvt2lDJ3NAg
Part 6
http://www.youtube.com/watch?v=zPce10ym ... re=related

