OS X's built-in dictionary has naughty words. Who knew? The following gallery will walk you through the steps it takes to censor your dictionary and prevent innocent young 'uns from looking up the proper meanings of these words. You'll need the Property List Editor, which is available as part of Apple's free Developer Tools.
Update: Parental Controls are a built-in but optional feature of OS X Tiger. They will be an even bigger built-in but optional feature of OS X Leopard. Those readers who feel that the existence of these controls are disturbing in and of themselves may want to take their concerns directly to Apple, who has built and implemented them in their operating system. Otherwise, non-native English speakers please take note that the post was written in a light hearted tone.