I searched the forums to see if this had already been covered and didn't find it so forgive me if its already been posted. But on this past 9/11 some genius at NASA decided to orbit a WB-57 at FL490 over Houston. Apparently it freaked some people out.
Flight path here http://flightaware.com/live/flight/N...8/history/20100911/2200Z/KEFD/KEFD
Article here http://www.chron.com/disp/story.mpl/metropolitan/7196771.html