[ScottJMurray]

I find that the best way to quiet my mind is to observe it spinning like a top until it finally loses its momentum. What a lot of you are talking about is a basic meditation technique. Whenever you find your mind off running around in some thoughts, notice that, and bring it back to a focus point. I do this when I'm running, and it's very pleasant and helpful for endurance. I don't try to force it to slow down, because it might still have things it needs to process.