I use mail and iCal at work, and often need to refer to agendas and other files which were sent by email. The new Message ID URL allows you to link to an email using the URL property of an iCal event. However, this involves displaying the header, copying and pasting.
The following AppleScript automates the process. Just select the email message, change to iCal, create or select the event, then run the script. You can then move the email out of your inbox and retrieve it later by a single click on the url link in the iCal event.
-- Script to read mess...