G'day James,
Checkout GPSResults -
www.manfred-fuchs.de/The d/l link for mac is
http://www.manfred-fuchs.de/GPSResultsMcV531.zipOr you can use ka72.com to import the data file and give you results and a google map overlay.
www.sportstracklive.com may also achieve what you want.
Google is your friend too :-)
Cheers,
Johnny
I'm obviously maturing because I was just going to reply "Solution is 'get a pc'" :-)