There are basically two approaches to map data. One is a bit mapped image with lat/lon coordinates for the corners of the map tile. There is no application awareness of features like roads on the map. This approach is used by Maemo Mapper and apparently Ovi maps. The other approach to maps is vector based where all characteristics of the map are defined with vectors. Ergo you know where every street on a map tiles is located and where it goes and can search for addresses and new routes. To perform these functions with a bit map approach you need to go to an external application which provides way-points as lat/lon that the application can position with on your map image. Both approaches have their advantages but my explanation isn't to favor one over the other but to put some clarity on the subject. Clearly bit map navigation requires information not stored on the device. Changing that isn't a "small thing" but an almost total rewrite of the application. I'm an N810 owner so I don't know without research what vector based navigation applications are available for the N900. A vector based application is the best answer for those who wish to do dynamic unplanned address searches. My approach with Maemo Mapper is to get my route files on my desktop ahead of time and move those GPX files to my N810. If you can't live with that, find another navigation application.