I wrote this random walk generator a while ago:

http://hotplate.co.nz/files/walk/

I should publish the code properly at some point, but it's all client side and not very complex, so if anyone wants to run their own local copy that is fine by me.

Accuracy or usefulness not guaranteed but it works well for the suburb where I live :)

I'd like to add a loop generator (find the endpoint, plot another random path back) but for the time being it assumes you walk to a place then walk directly back.

You can also specify the starting address in the URL, for making bookmarks or shortcuts for different starting addresses, e.g:

http://hotplate.co.nz/files/walk/#location=foo

To automatically plot a route from "foo".