There's always more than one way to do things with a Mac. I found by accident that double clicking the title bar of most apps will move it to the dock. So there's command M, clicking the yellow button, and double clicking the title-bar. Kind of like window shade. Useful sometimes.
[Editor's note: I did a quick search, and I don't think this particular version of this method has been published here before ... of course, as the database continues to grow, it's getting harder to say that with 100% certainty!]
Mac OS X Hints