I finally installed SleepWatcher, and used the .sleep script from this script on MacOSXHints. This combination makes my powerbook switch back to the multi-user login screen whenever it sleeps. This is great whenever I have to share the computer with someone else since I usually set up a quick user account for them.
The only deviation from the simple instructions was adding SleepWatcher’s default installation location to my global PATH variable. I store mine in /etc/profile, so I ran “sudo pico /etc/profile” and added “:/usr/local/sbin” to the end of the existing string. Everything else was the default install and process described on the MacOSXHints page.