Try it and see is I guess the best answer. Do you want bitmap mapping, or vector based (e.g. for navigation). I'd give maemo-mapper a try and look at both the Google maps and OpenStreetMap (OSM) data. If there's enough OSM data then either Navit or Roadmap should work for you (both are still pretty buggy in my experience, but at least you'll have some map data to play with as both use OSM).