It’s self-explanatory, really: While standing upright against a wall, close your eyes, reach down and go in for the kill.
This position is best for a mid-day quickie. You know, like, for those days when your boss is being a total a-hole, and meetings upon meetings make you want to blow off some major steam.
Oh, and since you’re standing, it’s easy to stop quickly if you do happen to be in the work bathroom and that same boss decides to claim the stall next to you.