I have the user and permission system for Part-DB ready (and I improved the english translation).
You can test the user system here: http://part-db.bplaced.net/part-en/startup.php
When you are not logged in, you can only read part information and dont make any edits. If you want to test edit mode, then login with username "user" and password "user" (without quotes).
I would happy if you would test it and give me some feedback.