title: iPhone SDK - On Device Locked or On Device Unlocked and application shown
body: <p>I need to find a way to detect when a device has been locked, or else a way to detect when the device has been unlocked, and sent straight to the app where it left off.  Is there some method like:  </p>
  
  <pre><code>- (void)applicationDidBecomeActiveAfterLockScreen:(UIApplication *)application
  </code></pre>