Your current location (assuming you have a GPS receiver) is plotted on the map. If you enable "Auto-Center", then the map will be panned automatically to follow your position. Or, you can use the stylus to point to a location on the map on which you would like to center the display. As you move, a red "track" is left behind you, telling you where you have been. You can clear this track at any time, or you can save it to a file, or load a track from a file.

Akin to tracks are "routes", which are green lines that usually describe where you want to go. You can download routes from anywhere to anywhere else, using latitude/longitude or standard addresses (e.g. "123 Main Street, 51122" or "5th Street and Broad Street, New York City, NY"), but you have to be connected to the internet. These routes, however, can be saved as GPX files and opened later. Many routes can be opened or downloaded, one after the other, and Maemo Mapper will lead you through all of them, consecutively.

The routes are downloaded from GPX Driving Directions Web Service, which is a regular web page, so alternatively you can use the Nokia 770/n800's web browser and save files from that page, or you can use a PC and save route files that you can then transfer to your Nokia device.

Once you have downloaded a route, Maemo Mapper will plot the route on the map, and if your route data has waypoints with descriptions in them (as do the routes from the above web service), then as you approach a waypoint, Maemo Mapper will pop up a message telling you what to do next (e.g. "Turn left at Freemont Avenue."). If you install flite and enable it in Maemo Mapper, then it will also speak the directions to you, just like an expensive in-car navigation system.

If you have a cell phone with data service, you can download a route from your current location to your destinatation in such a way that, if you get off track, it automatically re-downloads a new, re-calculated route, just like in-car navigation systems.

So many features and quirks... I really need to write them all down in some sort of documentation page. Lazy me!