Shrink App Windows Behind the App’s Dock Icon
For some reason, it irritated me when a minimized window shrunk to the Dock next to the Trash can. Shrink a lot of windows and they would all line up on the right-hand side of the Dock, next to the Trash. In Snow Leopard, they can now be shrunk behind the application’s icon in the Dock, where they belong.
Go to System Preferences>Dock and check “Minimize windows into application icon.”