title: Objective-C/Cocoa: Detect all keypresses
body: <p>Is it possible to run a method every time the user presses a key. Basically I want to run a sound like on the iPhone or iPad when a key is pressed. <strong>I do not want to detect key presses in my window or in a certain control, I want to detect ALL presses (such as when they are typing in Safari or something.</strong> I do not need to know what the key is. </p>
  
  <p>Thanks</p>