An interesting possibility with Stacks is that you can add the Trash to your dock, allowing you to easily view and restore recently deleted files. However, you can't just add the folder to the dock.
Instead, open a new finder window. Press Command-Shift-G to open the Go » Go to Folder dialog window. In the inputbox, type ~/.Trash and press Go.
Now you have a Finder window that displays the contents of your Trash. Unlike the "real" trash, however, you now can drag the proxy icon from that window's title bar to your dock. Finder will now create a Stack with the contents of your Trash.

