Have a look in the routes section Nick, some of the recent routes I've put in I did with bikeroutetoaster which allows you to download a gps file from it - you may need to register but it's free.
I only tend to use my Garmin watch if it's a different ride, and I seem to have lost a load of the ones I had

but have the ones below which I think you can download the file from.
Dragon Ride 2008 - [url]http://trail.motionbased.com/trail/activity/5997566[/url]
Rye and Back - [url]http://trail.motionbased.com/trail/activity/6245961[/url]
A Brighton run from some time (I think a test run for the watch but the file should be okay) - [url]http://trail.motionbased.com/trail/activity/6609742[/url]
My Grimpeurs' Challenge super hilly ride (100k ish) - [url]http://trail.motionbased.com/trail/activity/5905367[/url]
Lap of the Isle of Wight - [url]http://trail.motionbased.com/trail/activity/6939465[/url]