1. A method of using road signs to augment Global Positioning System (GPS) coordinate data for calculating a current position of a personal navigation device, the method comprising: obtaining recent GPS coordinate data with the personal navigation device; obtaining an image from a camera of the personal navigation device, the image showing areas surrounding a road on which the personal navigation device is traveling; recognizing a sign in the image by performing image processing on the image; and using a known position of the sign to augment the recent GPS coordinate data in order to more precisely determine an actual location of the personal navigation device.