nice post at http://blogs.msdn.com/sharepoint/archive/2007/05/14/understanding-the-sharepoint-calendar-and-how-to-export-it-to-ical-format.aspx. shame the is no conflict resolution ...
Microsoft SharePoint Full Article Link - Sharepoint calendar571a8301-2e6c-4e7e-b527-6379fc2d5f25|0|.0