gistfile1.m

// In AppDelegate.m

- (void)application:(UIApplication *)application 
  willChangeStatusBarOrientation:(UIInterfaceOrientation)newStatusBarOrientation duration:(NSTimeInterval)duration
{
    // Do some stuff with the orientation
    // UIOrientation is an enumerable defined as
    //
    //    typedef enum {
    //        UIInterfaceOrientationPortrait           = UIDeviceOrientationPortrait,
    //        UIInterfaceOrientationPortraitUpsideDown = UIDeviceOrientationPortraitUpsideDown,
    //        UIInterfaceOrientationLandscapeLeft      = UIDeviceOrientationLandscapeRight,
    //        UIInterfaceOrientationLandscapeRight     = UIDeviceOrientationLandscapeLeft
    //    } UIInterfaceOrientation;
}