Velocity and Height
Although tall pitchers have the advantages of long arms and long strides, there is a larger player universe of shorter pitchers, so shorter pitchers compensate with other attributes. Therefore, one would expect there to be little correlation between height and fastball velocity for Major Leaguers. I took the top 10% fastest pitches for each pitcher 2008-2009, and found little relationship between velocity and height.
Clearly, that's Wakefield who is the only pitcher unable to reach 80 MPH. Only pitchers between 6 feet and 6'6" have hit 100, which I suppose is interesting.
The inherent advantages of being tall are masked by looking at things this way. Still, I thought that I would be able to find some sort of height benefit by looking beyond raw velocity. I was wrong.
My idea was to look at the difference between the velocity normally estimated at the 50-foot mark by PITCHf/x cameras and the velocity estimated at home plate. Hypothetically, I thought, tall pitchers should release the ball closer to home plate than shorter pitchers, and therefore there should be a smaller difference between the starting and ending velocity of such a pitch. The data didn't back that up, and the more I think about it, the less the hypothesis makes sense.
I tried to fit a model using height, velocity, release point, and spin to predict the drop in velocity from start to finish. Kei Igawa lost the least velocity, and Igawa's been known in his brief time for an extremely long stride, while Shaun Marcum lost the most velocity, and I was able to find some research showing he had a short stride. Yet I think the list is mostly random.
If two objects, acted upon by different forces, are traveling at the same velocity at any given point with the same atmospherics, then the original point of impetus shouldn't really make a difference in their rate of deceleration. So unless a pitcher is releasing the ball within 50 feet, I think the initial velocity is the only PITCHf/x recording one needs, and height doesn't matter with this type of data.
Be sure to check out Eric Seidman's work on perceived velocity.