Bluewalks.com - collaborative online walking tours with Google Maps

I just came across this interesting site via Twitter:
http://bluewalks.com/

It describes itself as a cross between Wikipedia and Google Maps for walking tours -- where you can create walking tours with Google Maps and then other people can edit and update the maps.

Here's a sample 14km walking tour of Prague:
http://bluewalks.com/routes/2143

You can also embed the maps in other websites with HTML iframes.

It looks like a useful site with a lot of potential.

There are also similar sites for bike maps like Bikely.com, Bikemap.net, and MapMyRide.com (though the bike map sites don't have collaborative editing).