Bluewalks is a wiki for walking tours which uses Google Maps to create and share popular walking routes. Anyone can create a route and anyone can update the information of any route.
The walking routes are shown on the map with a polyline. Details about the length of the walk and location are shown in the map sidebar.
What makes these walks really useful, however, is that anyone can add points of interest along the route. The points of interest include things to see on the route and places to eat and drink. The POI are shown on the map by red markers and can contain photographs and detailed descriptions.