For those of using the auto-hide feature on the Dock, there are times when for some crazy reason the dock just doesn't show up. If this happens to you, hit Command + Option + D on the keyboard. This is a shortcut that turns on/off the auto-hiding feature. Once you hit this the Dock will show up and not be hidden. After you do what you need to do with the dock, you can hit this key combination again to turn the auto-hiding back on.