As I grow accustom to using the ‘stacks’ feature in Leopard I am finding some tweaks that you may be interested in.
Stacks, A Quick Low-Down
From my early and basic understanding, anything you place in the Dock to the right of the divider line, next to the trash can, becomes a Stack. Of course, you can right-click it and tell it to behave as a normal folder, rather than a Stack. Now, there are two other options with Stacks, sorting and viewing.
Stacks sit on the Dock in the order they are sorted. Thus, when you first start up Leopard the documents stack has a .pdf in it called “About Documents.” So, the .pdf icon is the first icon we see on the Dock with other icons from other documents in that folder in line behind it in alphabetical order.
When you click on a Stack, it can be viewed in a few different ways, a fan, a list and a grid. There’s also an automatic setting that must have some heavy math behind it to try and predict your mood.
The Tweaks
In Tiger, I always had the Apps folder on my Dock. Using it as a Stack is pretty interesting because it opens as a big icon grid and I don’t end up opening the Apps folder in Finder. However, how do I sort it? Which application deserves the spotlight on the Dock? Certainly not the address book, it is boring and I hardly use it. I was thinking maybe I could make my own icon and put it in the Apps folder so it would sit on the Dock. Then, I decided to search around and see if others have a better solution.
Here’s what I found, these great drawer or bin icons on this site and these instructions here. Basically, like my original thought, you chose one of the drawer icons from the set and copy it to your directory. You can rename it “0″ so that it is the first one in alphabetical order or follow some instructions on the link to change the time stamp date on the file. See my new drawers:

Of course, depending on how may apps you have, it may be a good idea to make a folder full of aliases(shortcuts) to apps that you use a lot, but they were not Dock-worthy or wouldn’t fit. Make that folder a Stack, and then you have all the applications you use frequently, without a cluttered Dock.
As I searched for ideas about modifying the Stacks, I also found this handy tid-bit of info. When you navigate the Stack as a grid, you really don’t have any animation, border or highlight to know which file your are choosing. The link takes you to a page with really brief instructions on how to remedy that. They also have instructions on how to turn it back off. I am trying it right now, but it really doesn’t seem up to par with Apple’s design skills, so maybe that is why they left it out. It looks decent, but the movement seems weird to me, there’s a pic on the link.