Wirelessly posted (Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Safari/530.17)
Does iCal support data detectors? Type the email address in the "Notes" (or is it "Comments"?) field. Close the event, then re-open it and see if you can click the email address.
I have no idea if this works, but I would think so.