The act of sharing one's location with one or more people in a technological or analog manner. Location sharing has traditionally involved concerns of privacy and security, as location data has fundamentally different mental perceptions towards it than data shared on the web. Because of there, strong systems are appearing that focus on the privacy and security of user data, as well as control over when and to whom this data is shared.
Some aspects of location sharing are territorial in nature. The popular location sharing service Foursquare allows one to mark their presence at a place and let others know that they've been there. Those who check in the most become "top dogs" or mayors. This is structurally identical to the territory marking of dogs and fire hydrants.
Sharing as a Social Utility
Other forms of location sharing exist to reduce uncertainty, such as temporarily sharing one's location with another in order to meet up with them more efficiently. One might share their location with a service such as Yelp! in order to determine which restaurants are nearby their area.