Well, there’s really no such thing. But you can make it work. In SA, create a realm where you want your WebDAV home folders to be. Give Auth/Browse access only to an admin. Then just create something like /etc/httpd/sites/WebDavUsers.conf and add the following:
<Directory "/WebDAV/folder/username"> <LimitExcept GET HEAD OPTIONS> require user username </LimitExcept> </Directory>
It seems that Digest authentication under OS X comes automagically from NetInfo which means we don’t have to edit any passwordfiles.
Now only the admin can see all the home folders, but each user can connect to http://server/username and see only their home.