Census Bureau Data Visualizations
The U.S. Census Bureau has a Data Visualization Gallery where they post weekly "explorations of Census data." Some of these strike me as unnecessary (does adding animation to the map of population density around Interstate 5 add any value to the data?), but strangely cool; (I will never be able to drive north from San Diego again without remembering this map!). At the very least, the site is a showcase for the data and (I hope) an inspiration to budding data visualizers!
Hat tip to LAist, a website about Los Angeles, that has a brief story (4 Cool Ways Of Visualizing Local Census Data) that links to some of their favorites that show how the population has been changing in Los Angeles and California relative to the rest of the country.