Here’re two utilities from CloudSync for Google Maps that help in creating markers and loading KMLinteresting. The first is a web-based interface for playing around with putting custom markers on a map (i.e., the GIcon and GMarker APIs). As a bonus, the tool generates the JavaScript you'll need as you play with the UI; there's an associated blog entry.

The second is CSGeoXML, a handy wrapper API that makes it easy to overlay local KML files into an embedded Google Map. This works around a limitation in the Google Maps GGeoXML API that requires that KML files be located on a publicly accessible server. There's also a blog entry for this one.

Source:→ Ajaxian