tells it to read the first file in geocaching.com format and create
a new file in GPX format.
+ This command will read from a Magellan unit attached to the first
+ serial port on a Linux system (device names will vary on other OSes)
+ and write them as a geocaching loc file.
+
+ gpsbabel -i magellan -f /dev/ttyS0 -o geo -F mag.loc
+
ADVANCED USAGE