I have a Garmin Nuvi 765T and I need to get a route created in google maps into my garmin. The route is a 6000KM motorcycle trip I am doing with a few friends.
The directions seemed easy enough to follow - you bookmark a tiny script in your browser "favorites" or "bookmarks" (I use FireFox) and then when you've generated your directions in Google you click on it and it pops up a long text file.
You save that as a GPX file and voila! You're all set.