Finding directions using a GPS unit is easy, however, not all file formats used by GPS companies are the same. Garmin and TomTom are two different companies competing in the navigation world. Both are capable of saving routes to the GPS unit, but they cannot use the same files. Using a third party file converter, you can change the format from the Garmin (.mps or .gdb) to the TomTom route format (.itn). As long as you have Java up-to-date, you should be able to quickly convert the file.