Pitching
Now there are no more excuses for me not being able to throw the ball 90 miles an hour. This Slate article is pretty interesting and says that it ain't height, it's something else:

What about growing taller, more massive pitchers? That doesn't necessarily make a difference, either. Small, slightly built pitchers like Dalkowski, the 5-foot-11 Pedro Martinez, and the 5-foot-10 Billy Wagner throw just as hard as giants such as Randy Johnson. The physical principle here is fairly simple. If two levers move at the same speed, the ball released from the longer lever will have more velocity. But as a lever becomes larger, it requires more torque to move. Randy's lever is larger; Wagner's moves more quickly. The trade-off makes their velocity roughly equal.

Anyway the article talks about how it seems that we have reached the limits of pitching ability, since the velocity seems to have topped out at 100 or so for the past half a century. No practical applications for this bit of knowledge, but still kinda interesting.