If you're using Entourage 2004, there is a feature called Project Center
that has a "share" feature that allows you to share your calendar entries
and other data with other users. This only works with Entourage; in other
words, it can't be shared with any client besides Entourage 2004.
In previous versions, calendar sharing isn't possible without an Exchange
Server. If an Exchange Server exists and free/busy server information is
entered properly, then other users should be able to see free/busy times in
your schedule. Furthermore, you can use Outlook to configure delegation
permissions for your calendar. That will allow other users you select to
see your calendar events.
