Really cool, but these heatmaps seem to be compiled from source code. I wonder how much the _actual_ distribution of keys pressed would differ. (I use paredit to write scheme code, and I'm assuming IDEs would skew the distribution in other languages.)
LISP really stands out for the parens. If I was primarily a LISP programmer, instead of an occasional Emacs tinkerer, then I'd be tempted to to put the parens on the g and h keys.