There may be other reasons you’d rather not have Dashboard available. For instance, if you run a lab of Macs in a school, you may not want the students wasting all their work time on the Asteroids video game widget or watching the (I am not making this up) Goblet of Fire movie release date countdown Widget. If you’d like to disable Dashboard, for either RAM usage or other reasons, here’s how to do it. It requires a trip to the Terminal, in /Applications/Utilities, but it’s not too hard to do.
How to kill the Dashboard once and for all!