I'm running OSX Snow Leopard (10.6.8) and am wondering how I can customize the multi touch features. I heard that Lion has a feature where three finger tap gives the definition of the highlighted word (ala the same feature as cntl+cmmd+d hover dictionary). Looking at the Trackpad System Preferences, there is a two finger tap for a right click, but there aren't any three finger tap options, only a three finger swipe option. Presumably, there is a way I can add a three finger tap option to Snow Leopard without switching to Lion. How can I add a setting for three finger tap to cause cntl-cmmd-d functionality?