Google Earth Plug-in API

When Google Maps was launched in 2005, few could have guessed the way map mashups would permeate the online world. Online maps had been just something you used to get directions or to find the ten nearest grocery stores. Google Maps and the Google Maps API proved that an online map was actually a rich canvas on which entire new applications could be built. Likewise, when Google Earth was launched, it revolutionized our view of the world, letting people fly around the planet at lightning speed and zoom in on rich high-resolution imagery, mountain ranges, and even 3D buildings. Yet there was a missing piece: there's never been a way to build your own 3D web applications using Google Earth, the way you can with Google Maps... until now.

Google announced the release of the new Google Earth Browser Plug-in, which brings the full power of Google Earth to the web, embeddable within your own web site. Driven by an extensive JavaScript API, you can control the camera; create lines, markers, and polygons; import 3D models from the web and overlay them anywhere on the planet. In fact, you can even overlay your content over different planets, stars, and galaxies by toggling Sky mode, letting you build 3D Google Sky mashups. You can also enable 3D buildings with a single line of JavaScript, attach JavaScript callbacks to mouse events, fetch KML data from the web, and more. Google’s goal is to open up the entire core of Google Earth to developers in the hopes that you'll build the next great geo-based 3D application, and change (yet again) how people view the world.

If you already are one of the 150,000 Maps API sites, and now want to 3D-enable it, now it is  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.

Internet: http://code.google.com/apis/earth.

Source: http://google-latlong.blogspot.com/2008/05/google-earth-meet-browser.html