title: Calculate distance from movement iOS MapKit
body: <p>I would like to be able to calculate distance based upon movement, as in user taps a start button and then when they reach their destination they tap a stop button. The app would calculate the actual distance travelled between the two points. </p>
  
  <p>I have the mapkit working in that I can get the start location and the map tracks movement I just need to add in the calculation of distance.</p>
  
  <p>Is this possible? If so any sample code would be much appreciated.</p>