Google Earth

Google Earth is a free, downloadable application developed by Google which is used to view Earth, the Moon, Mars and the night sky, where you can find information, and places. A notable feature of Google Earth is that major places like the Sydney Opera House are rendered in 3D, making them good to look at, as well as marking out that they are important. You can also observe 3D terrain like mountains and canyons, along with trenches under the ocean. The newest version of Google Earth also has a flight simulator built into it, which can be activated via hotkeys by pressing Ctrl-Alt-A.