title: iPhone, Map, Clickable non-rectangular areas
body: <p>Anyone have any ideas on how I could implement the following on the iPhone?  We have a map of the US, and it has different regions (climate regions, I believe) that are different colors.  They are not rectangular, and don't follow state or zip or county or any other defined lines.  So, our areas a very round-y and not even necessarily contiguous.</p>
  
  <p>I would LOVE to give our users the ability to click on their region and I would be able to tell from where they touched what region it was, but for the life of me, short of making many many many rectangles to do a best fit on the curves, I can't figure out how to do this.</p>
  
  <p>Any ideas?</p>
  
  <p>EDIT:  The regions could be as hard as this...  <a href="http://www.usna.usda.gov/Hardzone/ushzmap.html" rel="noreferrer">link text</a></p>