BTW - the "other" Mark's fourth point is 99.9% accurate, but not 100%. Since I'm in a nit picky mood, here's the difference. It's not to be the first to touch the ball "in the back court" but "after the ball has been in the back court".
What's the difference? The ball may go into the back court, hit an official, rebound into the front court and the subsequent touch would still count. I have also seen the extremely rare instance where the ball had some kind of backspin on it from a pass, hit in the back court and then spin back into the front court. Again, the subsequent touch would still count. OK - I've only seen that once, but I have seen the situation in which it hit an official 3 or 4 times.
Hey - I told you I was in a nit picky mood.