Do you want to stack your dock on such an effect? In fact, the lion would have this effect presets,Just do not open,Now let's open it manually:
First, open the "Terminal" (Applications ->Utilities),Then enter the following command:
defaults write com.apple.dock mouse-over-hilite-stack -bool TRUE;killall Dock
At this time the system may be slightly Caton seconds,And then re-opening the heap[……]