I just came across this page which has instructions on how to turn a google maps route into a GPS file of GPX format.

http://www.elsewhere.org/journal/gmaptogpx/

Its great because you can convert a google maps road route into lat long coords and thus extract the road real data from google maps. I'm working on some GPS code and need to test some paths through it and its hard work to manually set it all up so getting paths along proper roads is great. Its particularly useful right now cos you can edit the route in google maps with their nice n easy drag interface so I can force the road just where I want it.