You inspired me, so I tried to make a prank. It didn't work as well as yours did, but it went on for over an hour and a half.
I told a whole bunch of noobs that admins would drop admin bombs on the bridge to the right of the castle. I didn't think the word would spread but it did, and I didn't think it would go on as near as long. Well, here's the pics. Sorry that there's so many.