i think i found use for it at last by using ttmaps i have loaded the software good so far the next bit i don't understand, basically you load like maps in, Ariel ones or might be you can load google maps and use it as a field walking plotter for big fields, or anyone got something better for a tomtom ? 
http://ttmaps.free.fr/en/download.html

http://ttmaps.free.fr/en/download.html