Most of us are familiar with some form of geospatial application, whether we know it or not: From the GPS in a rental car to those handy maps that get us to the business meeting on time, we benefit from geolocated data.

In the search world, you may see geographically targeted advertising on your results page; in a taxicab, a screen on the back of the driver’s seat might suggest restaurants near your destination. Certainly, search giant Google is no stranger to the power of linking data to location. However, the world is a big place, and geospatial data is a lot richer than a collection of maps.

Most readers will be familiar with Google Maps but may not know that Google purchased Keyhole, Inc. in 2004 for its Earth Viewer, which underpins Google Earth. Google Earth provides all the functionality of Google Maps, but in 3D.

For those who haven’t yet "played" with Google Earth (launched in 2005), it lets you do things such as view an image of your home, office, or any place on earth; take a tour of the world; get driving directions from one place to another and "fly" the route; use Yellow Pages-like functionality and view your results as icons on a map; and view the 3D terrain of a location.

Like so many other programs, Google Earth has benefited from theuser-generated content (UGC) boom. There are untold numbers ofuser-uploaded photos and videos of locations all over the globe.Planning a trip? Take a look through the eyes of a local or anothervisitor, and get a view that is outside the scope of a tourism bureau(if the place you are heading even has one).

In fact, one ofthe most remarkable things about Google Earth is the way in which ithas benefited from UGC; much of the data in Google Earth was submittedby users. For example, when a restaurant owner creates a Gmail account,he or she can create a business listing for free that will then appearin a search for restaurants in the area.