I've seen a wooden outhouse where you have to sit on the throne and hold the door open with your foot while shooting.
Also shot one once that was a barrel-rocking-horse contraption attached to a rope that released targets down a zip wire. You had to rock to release the target. Then you were supposed to get 2 shots off from the rocking horse as the elk zipped by. Crazy.
Set up a bunch (maybe 8 or 10) of small 3D targets in a shooting gallery-type of arrangement, short range, and put a kitchen timer at the stake. Shooter must put an arrow in each target before 30 seconds runs out. This was fun.
If you have a creek or pond, have people shoot from canoes. A local club here has done this and it's a blast.
Overhead zip wires are cool - zip a large bird target over the shooter, not directly, but a little ways out. Make sure you advertise to bring flu flus.
Par 2- put the target in a field about 150-200 yards away. Shooters shoot once toward the target, then go to their arrow and shoot the target from wherever their first arrow hit.
That's all I got for now.
-Paul