Good work, BeanNeophyte. I remember trying to implement mouse gestures ages ago, and I never even thought of doing it this way. The result was a horribly slow thing that usually took about 30 seconds to get something simple done.

You could also modify it a little so that it uses a binary 'or'ing based upon the direction (for example, left=1, right=2, up=4, down=8), that way you can overwrite parts using different directions to make the gestures a little more complex.

For those of you that can't read that article (myself included): if you've ever wondered how the mouse gestures in games like Black and White were done, they're probably similar to this.