Alright, as long as I've got Debbie's interest whetted, I'd better go ahead and lay out a few more principals of The Pistol. I still strongly suggest that anyone about to take these up read the book, though--Pavel does a much better job laying down the finer points of this drill, and gives you photos to illustrate exactly what we're talking about.
On the way down, lean your upper body forward to help compensate as you go lower and lower.
Keep your weight focused on the heel of the foot that's flat on the deck. Try to imagine you're driving that heel into the ground.
Keep the lower leg of the one doing the supporting as straight up and down as possible. Imagine you're wearing a ski boot.
DO NOT BOUNCE once you're in the down position in order to help you get back up again.
Again, this one is a real goodie. There aren't many better of it's kind out there, with or without equipment.