Changing Unix password

If the users and the Unix box are not in
the same network you can always create a
cgi that the users acess to change the
password using a web page (there are a few
programs that can do that).
On the other hand, if the Unix box and the
users machines are in the same network, you
can install samba on the Unix box, and use
the "unix password sync" option in the
samba configuration. After doing that, the
user just need to go to the control
panel->passwords, and change the Microsoft
Networking Password. Mind you, for doing
this all the users need to login first to
the network, being the Unix machine the
domain master. If you allready have a
domain master and if your Unix supports pam
you can make unix autenticate using the
samba pam module.