GPS Devices
   Reviews of GPS receivers written by consumers at Epinions.com. Can be viewed by price range, brand, mapping capability, marine features.
   http://www.epinions.com/GPS_Devices

GPS Reviews
   Top-rated GPS handheld portable units, in-car systems, and PDA/computer plugin receivers. Where to find reviews in computer or technology publications and web sites. Links to reviews, with comments and credibility rating.
   http://www.consumersearch.com/www/electronics/gps/index.html

How Stuff Works: Global Positioning System Receivers
   Explanation of Global Positioning System (GPS) receivers.
   http://www.howstuffworks.com/gps.htm