The Global Positioning System (GPS) was initially developed and managed by the United States Department of Defense for military use but the technology has now trickled down to civilians and is use is being used freely, for navigation purposes. GPS is a global navigation satellite system (GNSS) and is the only functional system of its kind in the world. This is a list of resources on the web, that help people with GPS systems. The list includes reviews and information about GPS receivers, GPS mapping tools and gadget retailers who sell GPS receivers. Please feel free to add to this list, if you think something is missing.