We call it "Going Horizontal," or more commonly, "Go ho!" The idea is to dive to get that disc that otherwise is just out of reach, or dive to block it, hence making your body horizontal through the air.
You know how on ESPN or CNN Sports, they have their "Play of the Day?" (How annoying is that, when it's some guy chipping a golf ball up near the pin?) Every once in a while, they show a shortstop making the diving catch, or an outfielder leaping to grab something just above the wall. A diving attempt happens a few times in a baseball game, and it makes the TV news.
So at a recent tournament, I decided to count the number of diving attempts - at catches by the offense, at blocks by the defense. I chose a high-level game (why not?), DoG vs. Sub Zero.
They averaged three dives per point. Final score was something like 15-13. That would be 84 in a game.
And as to the one-handed leaping catch, that's even more common. Only in this game, unlike baseball, there's a defender there trying to keep the receiver from catching it.
And as if that weren't good enough, how about the play that we actually call a "greatest"? The player jumps from in bounds, to catch a disc out of bounds, and while still in the air throw it back in bounds, to be caught there by a teammate. Imagine an outfielder leaping out of bounds to catch a ball, and then throwing it to the first baseman while still in the air! Here's an example of it: http://www.port-a-field.com/TheGreatest.wmv