How to Forward an iCal Invitation
If you use Apple's iCal application to organize your schedule, you will find it useful to forward event invitations directly from the application itself. The iCal app is preinstalled on all Mac OS X computers and therefore is useful as a basic, readily available organization tool. You can easily forward your iCal events as long as you have Mac Mail set up simultaneously. When other users open iCal event emails, the program will automatically add the event to their iCals as well.
Click the "iCal" app on the Dock.
Select the event invitation you want to share.
Right-click the event and click "Mail Event."
Enter the email address of your recipient. Enter a message as well if you like.