Linux/Unix - how to enable one user to `sudo` without a password
How can a user be setup to sudo (or su -) without entering a password?
Solution 1:
You control sudo through the sudoers file. To edit this file, run sudo visudo.
I haven't tested this, but I think the following would allow all users in the "cdrom" group to run "sudo k3b" without needing a password:
%cdrom ALL = NOPASSWD: /usr/bin/k3b
Source: http://ubuntuforums.org/showthread.php?t=19236