The most expensive view is the street view in which the Navigon server sends continuously to the mobile phone detailed maps matching its position in a 2D view. Less expensive is the arrow view in which the server sends only arrows describing every maneuver to perform with spoken instructions. The user can also select only the map overview displaying the whole itinerary on one screen.
This solution of course requires a Bluetooth GPS receiver. The software is currently available for download from the Navigon website for seven Nokia and four Sony Ericsson handsets. Additional phones will be supported in the future.
According to Andreas Westhoff, Chief Sales Officer at Navigon: “this free Java solution has been released for brand exposure, we expect these users will get to know us and move to more upscale Navigon's solutions in the future”.
More information here