Questo è l'esempio riportato nella documentazione di Google Maps
	Codice PHP:
	
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
    <title>Google Maps API Example - Geocoding API</title>
    <script src="http://maps.google.com/maps?file=api&v=2.x&key=ABQIAAAAtOjLpIVcO8im8KJFR8pcMhQjskl1-YgiA_BGX2yRrf7htVrbmBTWZt39_v1rJ4xxwZZCEomegYBo1w" type="text/javascript"></script>
    <script type="text/javascript">
    //<![CDATA[
    var map = null;
    var geocoder = null;
    function load() {
      if (GBrowserIsCompatible()) {
        map = new GMap2(document.getElementById("map"));
        map.setCenter(new GLatLng(37.4419, -122.1419), 13);
        geocoder = new GClientGeocoder();
      }
    }
    function showAddress(address) {
      if (geocoder) {
        geocoder.getLatLng(
          address,
          function(point) {
            if (!point) {
              alert(address + " not found");
            } else {
              map.setCenter(point, 13);
              var marker = new GMarker(point);
              map.addOverlay(marker);
              marker.openInfoWindowHtml(address);
            }
          }
        );
      }
    }
    //]]>
    </script>
  </head>
  <body onload="load()" onunload="GUnload()">
    <form action="#" onsubmit="showAddress(this.address.value); return false">
      
        <input type="text" size="60" name="address" value="1600 Amphitheatre Pky, Mountain View, CA" />
        <input type="submit" value="Go!" />
      </p>
      <div id="map" style="width: 500px; height: 300px"></div>
    </form>
  </body>
</html> 
 
Qui l'indirizzo lo prende sa un textbox, ma lo puoi passare programmaticamente alla funzione javascript showAddress