How about all the RAAF FA18s parked out the back do a formation show,
Erm, 4 of them did.
or the C130 drop some stuff out the back using the parachute drogue system??
Agree that would be nifty. Saw a series of pictures at an airshow at Richmond a while ago depicting what has gone wrong in the past with such drops, not sure they could do it close enuf to the crowd line to make it interesting.