I've been on a productivity kick ever since I found that kGTD plugin for OmniOutliner, and I thought this script/app would be a nice addition to the collection of anyone who works in a collaborative environment, especially for those who live and die by email or just can't seem to remember to do X at X o'clock.
iCalMail 1.3 sets up a new calendar into which you can add events that will automatically email anyone you want at the event's time. iCalMail is clever too, allowing you to use different fields of the iCal event to compose each email, and the breakdown works like this:
event name -> subject
location -> attachment
attendees -> recipients
notes field -> message text
I haven't tested this yet, but it seems like a great idea, especially since there is a method for including attachments. Check out the script at ScriptBuilders, as well as more information at Chris J. Shull's site.