First: Explore every graph, chart, and table on Radical Cartography—wonderful, interesting material. I believe every graphic was made by Bill Rankin. The above graphic compares the relative sizes of the US and Europe.
Second, the meat and potatoes: The following maps display the population density and proportion of various groups across the country. Information is taken from the 2000 Census on six groups: white, black, Hispanic, Asian, Alaskan/ Native American, and Hawaiian/ Pacific Islander.
Third: The twelve images follow below (you may not be able to see them in your Dashboard or Reader, so visit the direct link to my entry). You can click each image for a larger view.