The Event Calendar now supports importing ICS feeds. For those of you who are not familiar with ICS, it's a normalized data format like XML, but specifically for calendars. When you click the "add to calendar" link in the module, it returns an ICS file that is readable by your calendar to add the event to iCal, Google Calendar, Outlook, etc.
With the new import feature, you can now import a static ICS file from your calendar. Just select one, several, or all of your events in your calendar tool, and run and export to an ICS file. This can be done very easily in Google Calendar and iCal. Then, place the file in event_calendar/import/YourFile.ics. Now, go to the URL www.yoursite.com/your-calendar/import/YourFile (Note the ".ics" is not needed). You should see a series of green success messages indicating the events have been added to the database. Anything that didn't make it through will return a red error message and the index of the attempted event in your ICS file.
But wait, there's more! ICS files can also be read as continuous, dynamic feeds to a calendar. If you're using shared calendaring, chances are you have a live ICS file living somewhere out on the web. With Google Calendar, it's very easy to get a URL for your calendar in XML, KML, or ICS format. Simply click on the "Feeds" tab on your Calendar page, and enter a title and a URL for the feed you'd like to include in your calendar. Now, every time a calendar page is viewed, it will mix in the latest data from your feed(s).
The only limitation is that because we don't always know too much about the events being imported, they currently come in as Announcements only. One way around this might be to examine the length of the Content or Summary property of the event and determine, if more than X characters, the import becomes a full event, and not an announcement. I find that most events created on a calendar tool like iCal, however, do not have long descriptions, and are best served as Announcements on your calendar.
I have not thoroughly tested this change. I have had success with two iCal exports and one Google feed. Test away, and enjoy.