TIP #1  |  Force Quit

Have an application that died on you, yet won't go away? OS X is remarkably robust when dealing with errant processes or memory leaks, and offers you a chance to force-quit a stuck application if you click and hold on the application's icon in the dock. However, sometimes an application can become so stuck that even a normal force-quit won't do the trick; if this happens, hold down the "Option" key on your keyboard while attempting to force quit. You'll find that after a couple of attempts, even the thorniest stuck application will quietly go away...