The Holy Grail of Bicycle Mapping features

http://toporoute.com seems to have implemented a feature that no other mapping-site (that I'm aware of) has: follow the road for you.

Meaning that if you click at one end of a curvy road, and then click a few miles away on the same road, the site will draw all of the points in between for you! This is the coolest thing since the Google Map came out itself..

I believe this is done by setting the Google Maps API to output = KML, but from what I've heard this is against the Google Terms of Service. I might just give it a shot on veloroutes.org and see what happens tho...