If you already are one of the 150,000 Maps API sites, and now want to 3D-enable it, we've made that possible with just a single line of JavaScript: just add the new G_SATELLITE_3D_MAP map type to your MapsAPI initialization code, and (for most common usages of Maps API) your site will "automagically" support Google Earth via a button in the maps view, with all your existing 2D map code now functioning in 3D as well.