How it works: Just search the site for a calendar of your choosing, click "subscribe" and that calendar will automatically be added to your iCal. Since it's a subscription-based calendar, it will automatically update whenever the author edits the calendar. You can also create and share your own calendars on iCalShare for free after registering with the site. Whether you're a Harvard student, a DC Young Democrat, or a movie buff, there's a calendar for you.
iCalShare was first launched in 2002 and spotlighted by Steve Jobs during his 2003 keynote speech. The site was created by Patrick Crowley, a technologist and long-time Mac user.