What the hell?
Frisbee. But more than that. [it's not allowed to be called 'Frisbee' - because it's a tradename]
It's a team game, played with a flying disc [frisbee to anyone else, 175gram UltraStar to those in the know] on a pitch.
Idea of the game?
Catch the disc in the 'Endzone'. [imagine an American Football Pitch, without the posts]
You can't run with the disc, if it hits the ground, the other team gets it, and there's also the other team who are trying the best to get in the way of who you're throwing it to. [without making contact though]
See more at http://www.ukultimate.com