I have been having a bit of a fiddle with googlemaps and created the site HERE
This is early days but I am quite pleased with the site, it allows an adminstrator to upload rides in GPX format which can then be viewed and displayed in Google Maps. A utility program works out the length of the ride and also calculates the furthest point from the start. This is used to "guess" the route destination which is shown on a summary map.
Rides can be viewed in detail and can also be downloaded in GPX format. After a huge amount of tinkering I havel also managed to create a "Fly Route" function which will drive a marker around the route after zooming into it.
I'd love to take credit for all of the code..but I can't. The GPX display classes are a GPL library I found that was written by Kaz Okuda I added a new function to it that allows you to fly the route.
I will soon publish the whole thing as a project for others to mess about with, but first I need to sort out the code a bit as it is not elegant.