We've switched the office over to a new calendar program. We've outgrown iCal and needed something beefier. After a lot of searching and trials, we decided upon CC Calendar (Scheduling Edition). The Calendar is essentially a Filemaker Pro file, which means you can share it with other users in the office. It's totally flexible and allows for tracking of rooms, people, and to-do items. And as far as iCal goes, it even offers syncing options.