Socrates said, “To find yourself, think for yourself.” We know he wasn’t speaking literally, but thanks to the increasing affordability of Global Positioning System (GPS) devices, they can do the thinking for you whether you’re in Athens, Greece or Athens, Georgia. Developed by the US Department of Defense for military tactics, GPS technology is a 24/7 radio navigation system that identifies and tracks the location of the GPS device virtually anytime, anywhere. GPS devices get their data from 24 satellites orbiting Earth. Locking into a minimum of three satellites determines your location in longitude and latitude. Some devices routinely lock into four satellites to provide altitude. Use of the satellite network is free—all you need is an unobstructed view of the sky, but while GPS devices will work under cloud cover and inside cars, they may falter under heavy tree canopies, inside tall buildings or tunnels, or dense urban areas with lots of skyscrapers. Not sure which brand or model to look at? Let Pronto’s GPS Buying Guide help you choose (see also Auto GPS Buying Guide).  More »