I've been having some lucid dreams recently, and there's a forum post on a forum somewhere that says you can astrally project from a dream. I had one dream where I projected successfully, and went back to my body shortly after and wrote something down, but when I woke up it was all a dream. And another where I tried but was was interrupted.
If when you're dreaming you have an astral body floating near your physical body, then if you're in a lucid dream can you transfer your consciousness to that astral body, bypassing the need to consciously produce one while staying awake? That would be a neat shortcut.