It usually comes in handy to know some stuff about this when taking pics of buddys and ski/snowboard whatever gets you going.
It is a easier to take a shot of some riding a rail nuff said. But when it comes to the big air trick shots. What I like to do is snap the pic on my digi cam just as there leaving the lip of the jump or pipe lip. Usually with a digital camera it takes a fraction of a second to actually snap the pic from when you press the botton and noramlly I wind up getting nice shots.