A system for synchronizing data for use in a navigation comprises a computing device and a vehicle onboard computer system. The computing device comprises an associated communication subsystem adapted for wireless communications, a user interface permitting entry of address data, and memory adapted to store the address data. The onboard computer comprises a communication subsystem for wireless communications with the computing device, memory to locally store address data, and a navigation system having a user interface that allows for selection of stored address data. The navigation system calculates a route based upon the selected address, displays the route on the user interface, and synchronizes address data using an information synchronization protocol. Changes or additions to the address data in the computing device are synchronized with local address data of the onboard computer, facilitating selection of addresses for route calculation.