Interactive 3-D-visualisation allows a very instructive view of statistical data. An impressive example is the comparison of the population distribution by night and by day in big towns. In the morning people go to work into the city and at night the go back into the agglomerations.
Statistics Zurich has built a 3-D-model based on census data. It’s in java, you can play with it and choose various views.
Zurich: Population density by day:
Zurich: Population density by night
The Java application and its technical description can be found on Statistics Zurich (in German only)
Similar models exist for other towns. See Washington