Just read an article about using iPods the help pitchers in the Majors. The main idea is that a pitcher can watch a video of every at bat with the opposing team members and see where they should throw the ball. And they can do this in between innings.
Sounds like the low tech version of what my dad used to do when he coached little league. He used to scout the other teams and write down where everyone of their players hit the ball. Then when we played the team, before each player batted he would adjust the position of our defenders as necessary. It worked quite well as I recall
Seems like there are all sort of visualization opportunities for ipoders. Sell videos of rides at amusement parks. Sell videos of people swinging their golf clubs at the range....
Actually I did something similar last summer in while golfing. I took our
little digital camera dad and I took turns filming each other's golf swing.
We then played them back in slow motion right on the camera. It turns out
that the club head was trailing my hands by a good 30 degrees. I made
adjustments to correct this and I've been a better (but still crappy)
golfer since then.