How to make the dock transparent in Mountain Lion? When I log in as a Guest user on Mountain Lion, i get a transparent dock with no background 'surface':


I can seem to find the settings that would make the dock in my own users' desktop look like this. Is it even possible for non-guest users?
To make the dock transparent in Mountain Lion type the following two commands in a terminal:

defaults write com.apple.dock hide-mirror -bool yes

killall Dock