This is great, and even better than something I asked for here:
http://forums.omnigroup.com/showthread.php?t=4968
Additions:
o Make all the events created in iCal include the URL so that you can navigate back to omnifocus. ie. omnifocus:///task/j6a_IXfVPs1 in the URL field of the calendar item
o Introduce another scheme, mail://.., that lets me point to mail items from within omnifocus messages. I find most of my work is generated from mail messages. After I do the work I need to reply to those emails. Which means I have to find them.