For a company events calendar, you can simply create a new Calendar folder in Public Folders and grant permissions through the Properties dialog for the folder.
Outlook 2007 adds the ability to send calendar files and publish your calendar for sharing. This supports just one way sync – the sender can update the calendar but others can't. If all users need the capability to update the calendar, you'll need to use one of the tools below.
|Tools in the Spotlight|
Gives managers, secretaries and co-workers an instant, web-based view of where people are, what they are doing, and when they are next available. AgendaX will seamlessly manage multiple time zones and allow global views of staff availability and resource allocation. AgendaX incorporates many features that allow you to take advantage of Outlook calendaring, Active Directory attributes and web views to give you the ultimate corporate resource portal. No client installation necessary and nothing is installed on Exchange Server. Supports all Exchange Server versions. New Version 6 available now!
Sample Outlook form application to maintain a central calendar. (Microsoft Office Update)
Use Sumatra Utilities to Insert server-specific or user-specific Holidays with no user intervention. It's customizable for different state or national holidays. You can define Free/Busy status, and have meetings that last specific times. Use it remove terminated users and their meetings cleanly from Exchange with customizable notification for guests. Find and remove broken meetings from resource calendars. Versions for Exchange 2003, 2007, and 2010 available.
For additional information on group calendaring, see Maintaining a Group Calendar in Outlook