Three ways to minimize, three ways to hide in OS X
Most Mac users know of two ways to minimize an application or Finder window: double click the top of the window or use the keyboard shortcut, Command + M. There is, however, a slight variation on the latter that can be useful, especially when you’ve got a kerjillion windows in an app or the Finder open. Command + Option + M minimizes all open single app or Finder windows, shunting them off to the Dock, which can be both a blessing and royal pain (i.e. making them all active again).
In order to keep things neat (Lion, Mountain Lion), and prevent the Dock from devolving into an endless string of indecipherably tiny icons, go to System Preferences > Dock and tick the “Minimize windows into application icon” (image above). Rather than minimizing one by one into the Dock, windows with slip neatly into the app’s Dock icon, easi.
This feature is also present in Snow Leopard, but you’ll need to activate it via the Terminal — See Mac OS X Hints.
App(s) be gone
Another neat trick in the same vein piggybacks on OS X’ Command + Tab app switching keyboard shortcut — hide an app. Activate switching by pressing and holding the Command key and then tapping Tab once. The app selector will remain and you can hide individual apps by the “W” key.
Want to hide the topmost app or the Finder? Press Command + H. To hide every app except the the topmost one by pressing Command + Option + H.
Know a nifty OS X tip or trick? Share it in the comments below…