On the way to creating my Digital History class I've thought about what kinds of critical inquiry makes the most sense in history course.  While  Digital History is a work in progress, I've decided mapping is one the most effective tools for students to embark upon. I've made this judgement through a bit of experimentation using open source information like the Negro Year Book available in Google Books.  Google Map Engine Lite provides a pretty flexible tool. As you can see from this old test map, playing around with specific layers to provide information can create unique maps.