@johnbaichtal had this to say:

Dude, quadrotors are scary. http://www.youtube.com/watch?v=YQIMGV5vtd4

Watching an army of nano quadrotors fly in formation, swarm, and return to formation was almost surreal.  It really did feel like I was watching a clip out of Terminator.  If you get a chance, watch the other videos by this same uploader, “TheDemel” as they feature these quadrotors flying/diving through hoops, flying/diving through thrown hoops, and perching on vertically mounted landing pads.