File this under shortcuts-that-might-be-ancient-but-we-never-knew: with just a quick modifier key, you can show any dock item in the Finder, whether it's an application or a file in a stack.
In Mac OS X, if you hold down the Command Key while clicking on an item in your dock, it will open up the location of the file / application in the Finder.
Found this on accident.
This is particularly handy for those occasions where you want to edit or move an application or file, but don't want to go searching for it. And, while stacks have that "show in Finder button" it can get pretty annoying to search it out when you have a stack with more than a few files in it — this speeds things up quite nicely. I'll admit, this blew my mind a little.