title: MKAnnotationView Default Callout Opacity
body: <p>I'm using MKAnnotationView for pins &amp; callouts and I realize that there is the option to create a custom callout with a custom animation which I may end up doing if it's my only choice...  However does anyone know if there is a way to simply alter the default opacity of the callout view for these?</p>
  
  <p>I have some pins on the map which I want of a lower opacity because they aren't sponsored listings.  Not to mention the default opacity is already a little too low for my purposes.</p>
  
  <p>Am I stuck with subclassing or can I pull this off without violating any rules?  :)</p>