How can I get Mac OSX 10.3 iCal to import my Org-exported .ics files?
When using iCal under Apple MacOS X Tiger, you can create a new calendar OrgMode (the default name for the calendar created by C-c C-e c, see the variables org-icalendar-combined-name and org-combined-agenda-icalendar-file). Then set Org-mode to overwrite the corresponding file ~/Library/Calendars/OrgMode.ics. You may even use AppleScript to make iCal re-read the calendar files each time a new version of OrgMode.ics is produced.