file:///Users/nero/Desktop/map%20to%20Joe's.pdf
When you click on the bold "URL" label, you will get a menu that says "Go to Location." Click on that, and the file will open. This is very handy for lots of reasons.
The lame part is that this is all text based. You can't drag the file to the URL field, which is weird since drag-and-drop works in so many other places in Mac OS X. You have to type the thing in, including the %20's for every space and the file:// protocol part. But if you really want to attach files to iCal events, this is one way to do it. Any suggestions for making this a little easier? Quick ways to get the URL of a file?

