Joe Golike and Sha Hwang of Trulia take a deeper look at when crime typically happens throughout the day in 25 big cities across the United States. The result, When does crime happen? is a set of interactive stacked area charts that allow for detailed comparison between different types of crimes and high-level comparison between different cities. On hover, a tooltip reveals more detailed information and the percentage of reported crimes per type and hour. I think the small multiples work pretty fine for comparison over cities and the charts show the data in a readable and elegant way. The visualization is built in HTML5 using Protovis and the underlying data comes from SpotCrime. Read more about their findings on the Trulia Insights blog.