The short animation titled "Deluge" [bengler.no] by Even Westvang reveals how public data can be analyzed to reveal potentially interesting patterns. In particular, this movie demonstrates the patterns of 300.000 Norwegians moving house, by cross-referencing the tax records of about 4 million individual Norwegians from 2006 and 2007.
In the movie, the data is filtered by paramaters like yearly income or age, and a distinction is made between 'incoming' (red) and 'outgoing' (blue) citizens. As a result, one can perceive that elderly people generally move over relatively short distances, while high-earners tend to move out of the big cities to the shores.
Interestingly, in Norway all the incomes and fortunes of all tax paying individuals are made public every year, which consists of the full name, year of birth, postal code and their attendant financial data.
Watch the movie below.