To have your Facebook events show up in iCal (or other iCalendar compatible program):
- Go to your Facebook Events page.
- Select “Export Events” (link near the top left).
- Copy the link they give you.
- Switch to iCal (or your other calendar application).
- Select “Subscribe…” from the “Calendar” menu (or the equivalent for non-iCal apps) and paste in the link from Facebook. Then select the “Subscribe” button to add the Facebook events to your calendar.