I just discovered that SharePoint v3 / 2007 has a two way sync with calendars in Outlook, whereas before it only had a one way sync in the v2 / 2003 version.
So you create a Calendar in a SharePoint site, then go under Actions, select Connect to Outlook. Outlook will then ask you if it is OK to link to the site, etc. Once you have added the site to your Outlook, you can drag/drop events from your main calendar, or create new events directly in the SharePoint calendar. Continue reading SharePoint 2007 2-way sync with Oulook Calendars