title: Passing touches between stacked UIWindows?
body: <p>I have two windows -- a front one, and a back one.  The front one is used to overlay some stuff on top of the back one. I want to be able to capture touches on some parts of the front window, but not others; I want the front window to receive touches in some areas, but pass them through to the back window in others.</p>
  
  <p>Any ideas as to how I'd do this?</p>