A graphical mapping system configured to display mapping information on a handheld device is disclosed. The system includes an image map database configured to store map data for a plurality of geographic areas, which is useful for generating graphical maps. The system further includes a vector map database configured to store vector map data, which is useful for generating vector “overlays” that correspond to the graphical maps. In response to a mapping request from a handheld device, a set of image mapping data and a corresponding set of vector mapping data, both associated with a given geographic location, are retrievable.