What about other substances like caffeine? Any personal experiences? Links?
Caffeine doesn't have a good affect on my dreams. I once drank one of those five hour energy drinks just before bed... not a good idea. It gave me some awesome HI, but it took ages to actually get to sleep, and I didn't have hardly any recall the next morning.

Vitamin B6 is a really good substance for dreaming, though. I've never had any personal experiences with it, but I've heard that it does help.

(And I believe this thread should go in Lucid Aids...)