New York Times has a collection of different mapping tools. For example, you can see the racial distribution by state, county, neighborhood. You can see what percentage of households are paying more than 30% of their income for a mortgage. Hours of fun are possible--and maybe something interesting.
UPDATE: One of the maps under Housing and Families shows the percentage of same-sex couples by census tract. Not surprisingly, there are parts of San Francisco with 17%, Provincetown, Mass. (12%), and a few big cities with high concentrations. Key West, Florida, in spite of its reputation, is 5% same-sex couple households--and there are a number of census tracts in places like Oklahoma with similar percentages, such as census tract 20704, or census tract 9501 in Texas, which is 10%.