Google has enhanced its Maps API and MapsGoogle will now display EarthGoogle KML files. Here is an example. The KML file is appended to the maps dot google URL. Use a web service like Gmaps Pedometer to build trace routes. Use Gmap to GPX and create a GPX file. This file can be imported into Google Earth where the . KML can be edited. The paid Google Earth Plus version will shortcut the above steps as it has all of the features in one place.