How can I create an iCal alarm that doesn't get synced to all my computers? I want to run an Automator script every three weeks that sends an email. I know how to create an alarm in iCal to run the automator script that sends the email. The problem is that the iCal event gets synced to all three of my Macs and they all try to run the script. The script only exists on one of the computers so I get error messages on the other two.

How can I create an event in iCal that doesn't get synced to all my Macs?
You can create many calendars in iCal, and sync only the ones you choose to other devices. So create a calendar to contain these alarms.