A method and apparatus for determining position using a handheld personal
computer. A cradle is disclosed that that is adapted to couple to a
handheld personal computer. In one embodiment, the cradle includes
projecting members that capture the handheld personal computer and hold it
securely in place. The cradle includes a position determining system that
is adapted to determine position. Upon coupling the cradle to a handheld
personal computer, the cradle is operable to determine position. Once
position is determined, the determined position is displayed on the
display of the handheld personal computer. The display can include a
display of a moving map and an icon indicating the current position
relative to the map. All required hardware and software for storing the
map database and for determining position are included within the cradle.