Maps are both tools of navigation and encapsulations of the zeitgeist: they tell us where to go, but also where we already are. The new Google Earth software program (downloadable free at presents highly detailed satellite images of the entire planet, an awe-inspiring, God's-eye view of the globe. Type in a location, and the software executes a vertiginous, diving swoop from outer space, stopping finally a few thousand feet above your house, for example, or Versailles, or an IHOP in Trenton, New Jersey. Google Earth overlays information from Google Local (roads, borders, shops) and also lets you adjust your viewing perspective in 3-D, so you can simulate a low-altitude flyover.

The genius—and currency—of Google Earth, however, isn't in its high-tech bells and whistles, but rather in its integration of user-created content, a.k.a. mash-ups. By publishing in an open-source format, Google has encouraged users and other businesses to make and share their map annotations and applications, leading to an explosion of grassroots mapmaking. At sites like and, you'll find downloads of everything from the useful to the arcane, locating hotels and restaurants, homes of the "rich and famous," and nearly every drive-in movie theater in America—not to mention real-time traffic and weather maps, views of the earth at night, the specific location of commercial airplanes in mid flight, and much more.