Birthdays and anniversaries are important to remember, sure. But we all know how best to use calendars: To know when your favorite sports team is playing. Enter iCalendarFactory, which adds sports teams' schedules to your calendar.
It only syncs 30 days at a time right now, and schedules are manually uploaded by the developer, so it's a little more hands-on than we'd like to see. But it's certainly worth a look-see. So far the NBA, NHL, MLB and NFL are available, as well as a slew of European futbol leagues.