A method and system for operating a hand-held computer system for navigation. Embodiments of the present invention includes novel improvements to a navigation method and implementation through a device, which can include inertial and/or magnetic field sensors integrated within a hand held device. The method can include using a single-fix method or a dual-fix method. The single fix method includes monitoring travel distance or time for a pre-specified condition and updating the heading from a dead reckoning process based on a first position fix by using a map. The dual-fix method includes obtaining a second position fix and updating the heading based on the difference in displacement vectors from the dead reckoning process based on the first position fix.