Well, Box.net does not offer free WebDAV access anymore. So anyone looking for a free WebDAV server can try CloudSafe:
http://www.cloudsafe.com
1) Register
2) Create a safe
3) Enable WebDAV access (you will see the login credentials for your safe)
Nice add on: You can give trusted contacts access to your safe in case of emergency. Or you can share the safe content with family, colleagues, clients.
Best,
R.