I volunteered to help out a local gaming convention by providing a scheduling application. It's a modified version of phpScheduleIt, and you can see it here
Things taken out:
1. Advanced Resources
2. Multiday events
1. Tracks (aka Categories). Each event can have any number of categories (like Board Game, RPG, etc). The Categories are dynamic, like a resource. Schedule coloring is based on this instead of participation.
2. Clicking on Join skips the Invite step.
3. Biggest change: Uses the site's drupal authorization with a heavily modified IsLoggedIn function.
4. Generates PDF reports for admin users (signup sheets and table schedules).
5. Added Title and Max Participants to each event.
6. Schedule defaults to the day of the event instead of today. Removed date navigation at bottom.
Bugs I never got around to fixing:
1. Displays "\" in Summary texts.
2. Logging out of one account in drupal and logging into a different one doesn't change the user in phpScheduleIt.
If anyone would like the code for this or has questions about how it works, let me know. Some of it is pretty ugly.