By default, the Mac Dock is located on the bottom of the screen. If you prefer it on the left or right side of the screen, this is a neat little trick that will allow you to pin the Mac Dock to the top or bottom corner of either side.
To get started, be sure that your Dock position is already set to the left or right. You can do this via the Apple menu (Apple -> Dock -> Position). Next, open Terminal and enter one of the following commands:
pins Dock to bottom corner
defaults write com.apple.dock pinning -string end
pins Dock to top corner
defaults write com.apple.dock pinning -string start
You’ll then need to restart the Dock by entering this Terminal command:
If you want to put the Dock back in it’s default center position, you’ll need to enter this command in Terminal:
defaults write com.apple.dock pinning -string middle
Don’t forget to restart the Dock again:
Which position is your favorite for the Mac Dock?
via The Sweet Setup