title: sectioned tableview index selection highlighting
body: <p>I feel this should be a simple property, but for the life of me I've searched and cannot find the answer.</p>
  
  <p>I have a tableview index to the right of my table.  When selected, it grays out everything.  I'd like to mimic the iPod app, whereby when the index itself is selected, it is semi-transparent (alpha of maybe .4f).</p>
  
  <p>Any ideas?</p>