title: Detecting iOS orientation change instantly
body: <p>I have a game in which the orientation of the device affects the state of the game. The user must quickly switch between Landscape, Portrait, and Reverse Landscape orientations. So far I've been registering the game for orientation notifications via:</p>
  
  <pre><code>[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
  </code></pre>
  
  <p>But it is far too slow - there seems to be about a second delay between rotating the phone and the notification actually being fired. I need a way to INSTANTLY detect changes in the device's orientation. I have tried experimenting with the gyroscope, but am not yet familiar enough with it to know whether or not it is the solution I am looking for.</p>