One of the most important capabilities that smartphones now have is knowing where they are. More than desktops, laptops, personal navigation devices or even tablets, which are harder to take with you, a smartphone can combine its location with many other pieces of data to make new services available.
There are at least 10 different systems in use or being developed that a phone could use to identify its location. In most cases, several are used in combination, with one stepping in where another becomes less effective.
