I ran across Gmaps Pedometer as a way to measure the length of my bicycle commute from home to work (via bikejournal.com. It combines the Google Maps interface with the ability to double-click on the map to set markers for your route. It also includes the ability to show an elevation profile of your route. So now I know that I have a 20% hill climb near the end of my ride back home (200ft. elevation gain in 1000ft of cycling).