Passwords for MySQL, Apache, Samba -- all at once?

dschuetz writes "I'm setting up a system that uses Samba for filesystem support, a MySQL database for modifying/editing data, and Apache/PHP for parsing/displaying the data. All three require authentication. All three currently have "group" accounts.

I want to get to one-user accounts, but don't want to have to deal with updating three or four different places whenever someone comes on or changes their password. Is there any solution available that will allow me to point all those services to a single authentication system? I've heard a little about PAM, but don't know much about it (and I don't think it'll work with MySQL, either). "