title: How do you make a UIBarButtonItem animation flip?
body: <p>In the iPod app on the iPhone there is a UIBarButtonItem in the upper right toolbar that flips between the song and track listings for the album.  When you select the button, the button itself does a flip animation.</p>
  
  <p>Is there a way to do this with:</p>
  
  <pre>
  CGContextRef context = UIGraphicsGetCurrentContext();
  [UIView beginAnimations:nil context:context];
  
  [UIView setAnimationTransition: UIViewAnimationTransitionFlipFromLeft forView:[self superview] cache:YES];
  </pre>
  
  <p>Do I need to make a UIBarButtonItem with initWithCustomView vs. initWithImage to achieve this? </p>