title: Add an icon (mac & pc) to a file with Cocoa
body: <p>I want to add an icon (icns &amp; ico) to a file within my iPhone app and I'm not quite sure where to start looking! So when this file is viewed in <em>Finder</em> or <em>Windows Explorer</em> it will have a custom icon.</p>
  
  <p>Can anyone point me in the right direction?</p>