I've been using geocontext.org for a different application (finding contours on ski race courses). But I've also played with it for biking.

It's a lot like Google Maps in that you can chart your route by clicking on waypoints.

The great thing about it is that it gives you a profile of the ride, so you can see what you have ahead of you as far as climbs and descents.

The down side is that follows a straight line, so you have to click on every little curve (whereas Google Maps follows the road). Also, it is from Eastern Europe, so make sure you find the 'EN' button on the home page if English is all you speak.

Probably not the perfect bike mapping website, but still fun to play with if you're riding in the mountains.