This online video got me a good bit of the way along:
http://mustardseedmedia.com/podcast/episode34
On this podcast, Bob shows how to import any iCal feed of events into your Drupal site and displaying them in a Views-driven calendar on your site. (This means importing your Google or Yahoo! calendars or any other calendar system that puts out a feed in iCal format) This is tasty stuff! Want to have the Drupal calendar delete nodes once they're deleted from the feed? Check out this patch and give it a try. Episode Links Feed API, iCal Parser, Feed API Mapper
I am stuck on populating the Organic Group field of the newly created node.