http://drupal.org/project/alt_login From the project page: "This module provides a simple interface that allows registered users to use a login name which is different than their username." I'm giving up all of my contrib modules to focus on co-maintaining the Project* suite. I'll only be maintaining this module for another 30-60 days, so please contact me if you're interested in adopting it. Otherwise it will be abandoned and unmaintained. hunmonk