You could try the [url=http://www.polyphasicsociety.com/polyphasic-sleep/overviews/uberman-2/]Uberman Sleep Cycle[/url], it's supposed to train your body to instantly go into REM during the brief times you sleep and give you very vivid, lucid dreams. I tried it once but my schedule didn't allow for me to continue, plus I started getting bored with so much extra time on my hands since I was only sleeping about an added total of 3 hours, I didn't know what to do with myself. I may try it again someday if I have the time.