Comparative Histograms in ggplot2

I have been doing a lot of work with limited dependent variables lately.  With my push for better visualization as a means to communicate findings (as opposed to relying on tables of coefficients), I have had to develop some strategies for building effective comparative histograms.  I did some of this in my recent JPART and continue to use the same code for other projects (mostly, my risk perception and trust work).  I thought some might like to see how simple it is to create nice comparative histograms for categorical dependent variables:

New Paper on Punctuated Equilibrium Theory and Organizational History

I am almost done with the textbook so I am getting back to (or on to) a variety of writing projects.  This is my recent paper getting back in the PET (punctuation equilibrium theory) game.

Paper after the break...