title: add mkannotation on touch map
body: <p>I want to add a mkannotation to my mkmapview when an user taps over the map so they can choose a location.</p>
  
  <p>I've read about the drag&amp;drop but that's a bit annoying if you want to move to the other corner of the city because you have to move step by step the pin.</p>
  
  <p>How can I get the coordinate where a user taps and move my pin there?</p>
  
  <p>Thanks!</p>