Thanks for the wonderful feedback on the original post. As requested, I've made some changes to the prototype.
I tried to make the innings more defined, I moved some of the data, and differentiated some colors. I added in the pitchers names, and made the code on the left hand side less mysterious. There's now a pitch count bar at the bottom. I also extended the plate appearance end-lines from the top to the bottom.
Anything else you'd like to see changed or added? Once I get everything smoothed out, I'm planning on posting charts like this for particularly intriguing games this season. There might be some interesting trends that jump out.
I'd write a fancy graphics script to parse the data from pitch-by-pitch sources for every game, and automatically generate a graphic... but that's beyond my technical capabilities. Unless someone out there can lend a hand, I'll just continue to put these together using retrosheet, MS paint, notepad, and my own misplaced sense of persistence.
One last item: any suggestions for a name for this thing? I've been calling it a pitch graph and a pitch chart, but those just don't have a nice ring to them...