- Bring back “Save As” by Holding the Option key when in the File menu. Doing this reveals many other alternative options including this one, like the “Library” folder under the “Go” menu, which is usually hidden.
- Preview any file in Quick Look by tapping the trackpad with three fingers. This works for images, documents, and any other file Quick Look works on.
- Launch Mountain Lion’s new Dictation app by pressing the Function key (fn) twice. You can customize this shortcut in the Dictation and Speech System Preferences.
- Command + Options + F5 opens the Accessibility Options in any application or window, giving you access to zoom, VoiceOver, mouse and keyboard options, and display contrast controls at any time.
- Rename files, move them to iCloud or another folder location, or even revert to previously saved versions from the title bar In Preview, TextEdit, and other bundled applications. Just hover over the filename in the title bar to reveal the drop-down menu.
- Click the Sort bar in Mail.app to zoom to the top of your inbox.
- Swipe forward or back with two fingers to navigate forward and back in apps like the App Store, iTunes, and Dictionary.
- Launch apps from Launchpad by clicking the Launchpad icon and immediately typing the name of the application. As you type, Launchpad will narrow the results for you, and you can press enter when the correct app is highlighted to launch it. It makes for a nice application launcher.
- Pinch to zoom in on TextEdit documents, and move your fingers apart to zoom out.
- Disable Notification Center for one day by Alt + Left-Clicking on the Notifications menu in the upper right corner of the screen.
- Look up a word in the dictionary by tapping it with three fingers. If you’re not in love with this shortcut—as some people prefer the three-finger tap for other purposes—you can turn it off in the Trackpad section of System Preferences. Note: This only works in some applications, like Safari, Finder, and other Apple apps. It’s not limited to only Apple apps, but it doesn’t work in Google Chrome at the moment.