After you have installed Google Earth, you may want to explore some of the interesting data layers being published by other folks on the web. Anyone can publish content for Google Earth using our geographic markup language (KML). To view these, simply click the links below. They will appear in your “Places” list. To save them for future use, right-click on the feed you wish to save and select “Save to My Places.”
And now, Google Earth is officially available for MacOSX 10.4 Tiger. Obviously, because of the "heavyness" of GEarth, a processor >=G4-1Ghz is recommended... IMHO ;) .