Upon finding a cicada, the female wasp paralyzes it and carries it back to her underground burrow, where she lays an egg on it. When the egg hatches, the larvae eats the cicada. What a way to go! There's a website with good photos and info on these guys out there.

Days after I told my other friend Matt of the existance of these large wasps, he happened to actually see one doing its thing, and luckily for me had his camera on hand to get these shots: