It may be possible to transfer ownership to another member of your domain only if you on an exchange platform and the calendar is not your default cal.

Simply open your Outlook 2007 > Calendar. Select the calender from the calender list and right click it to get to the properties window. Once the properties window opens select the permissions tab. here you will be able to add anyone to give permissions to. Only the original owner can give ownership to another user.

Hope this helps.