Abstract: A navigation system is provided for offering navigational assistance to a mobile user. The navigation system receives GPS position information signals which are processed to determine current position latitude and longitude coordinates and direction of travel. A destination data base includes destination related information preferably stored on an interfacable memory card and contains menu categories and subcategories for classifying destinations and text information. The memory card may include a user modifiable data base. Data information is provided with a data identification code which is required to match the user identification code assigned to a given system for authorized access thereto. Such data could be provided for a period of time set to expire. User selectable menu controls enable the user to sequence through the menu of categories and destinations and select a desired destination.