OK ... so I explain it a little bit in more details:
pwauth is the "linux authentification tool" - see here: http://code.google.com/p/pwauth/
In my NAS, there is a file where the users are in. For example, for my QNAP system, it is found here: /mnt/ext/opt/apache/bin/pwauth. ownCloud, for example, has a nice plugin, where you can use and it gets all users from this table. So you don't need to set them up seperately.
The 2nd thing is - It would be great to have a login dialog on the "normal" page, not only in the admin interface. So the user can login and view his pictures without getting into the admin-interface first.
Maybe you could make this optional as a setting?
Cheers,
Georg