How to turn Mac OS X Dashboard offというエントリーより。

Short of installing previously-mentioned Bye Bye Dashboard, Mac OS X Hints describes how to disable (and renable) Dashboard by entering the following commands at the Terminal:



10.4: How to disable (and enable) Dashboardというエントリーに詳しく書かれていますが、以下の通り。

To turn Dashboard off:
defaults write mcx-disabled -boolean YES

To turn Dashboard on:
defaults write mcx-disabled -boolean NO

You have to restart the Dock after making either change for it to take effect:
killall Dock