More posibilities with adresses on dashboards and views

When having a client/volunteer/… list with addresses, I would like to be able to summarize (in a dashboard or view) the amount of people by geographical region. Like by State in the USA, or by province in Belgium or France. So a graph that tells me I have 100 clients in region/province/state A and 150 in region/province/state B. Without having to add a separate region/province/state column to be filled in by hand…