Add spacers to your Mac OS X Dock

Found this handy hint somewhere on the net

To add a Blank Icon (Space) to the dock in Mac OS X, open up and enter this. Enter it as many times as you want spaces. Error on too many.

defaults write persistent-apps -array-add '{"tile-type"="spacer-tile";}'
killall Dock

To remove them, just drag them up and out of the Dock like any other icon. To move them around, click and drag.