Google Earth 6 is the latest version of the desktop version of Google Earth. Google Earth lets you navigate around towns, cities, countries, etc. Google has announced that they have Google Street View integration and 3D trees.
Street View in Google Earth
You will notice that Pegman is docked in the navigation controls of Google Earth. Pick up Pegman and drop him in the blue roads to view what the ground looks like.
Google has planted virtual trees in Google Earth. This includes the Japanese Maple and the East African Cordia. About 80 million Google Earth trees have been planted so far.
You can download Google Earth 6 from http://earth.google.com.