Looking south, here's roughly what the moon looked like when I set out:
A little later, it looked like this:
Notice the way it rotates as it moves across the sky. The interesting thing is that if you imagine a line running between the points of the moon and extend that line down, where it intersects the horizon is due south.
Obviously, this technique is useful for orientation only when the moon is visible and not full. But I often find myself using it to get my bearings when I'm out before sunrise on the winding paths that cut through the grid of Thornton's city streets.
It could come in handy some day. And if nothing else, it is, as Tristan Gooley describes it, a neat party trick.