. Storing this here incase the location goes down. http://de.60.5646.static.theplanet.com/samples/distance.php.html

geo.php

		/**
		 * This section of code was taken from here
		 * http://de.60.5646.static.theplanet.com/samples/distance.php.html
		 */

function calcDistance($lat, $long2, $lat2, $long2, $unit='m')
{
	$theta	= $lon1 - $lon2;
	$dist 	= sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
	$dist 	= acos($dist);
	$dist 	= rad2deg($dist);
	$miles 	= $dist * 60 * 1.1515;
	$unit 	= strtoupper($unit);

	switch($unit){
		case 'K':
			return ($miles * 1.609344);
		case 'N':
			return ($miles * 0.8684);
		default:
			return $miles;
	}
}