Since you can not send an email notification to anyone other than yourself in iCal, would anyone know how to write an AppleScript that would send email notifications to a person, or a group of people, based on the alarm and the iCal event?
The way that it might work is that the alarm would trigger, opening an AppleScript file that sends the email. It could work in the background or perhaps present you with a dialog box where you could pick what recipients that you want to get the alarm. One problem with this approach is that if the alarm triggered while you were doing a presentation to a group of people from your office, you might have an annoying dialog box come up asking who you want to notify that there is a surprise party for your coworker on Friday at lunch.