Here’s a great tip that creates a nice hover effect when your mouse goes over an application (or folder) within a Leopard stack. Why this isn’t enabled by default in Leopard is beyond me, because it makes navigating within stacks a whole lot easier. Don’t miss out, here’s how to activate it:

Launch the Terminal and type the following command:
defaults write com.apple.dock mouse-over-hilte-stack -boolean yes

then, you’ll have to restart the Dock by issuing the following command:
killall Dock

To disable the hover highlights, type: