A sobering collection of choropleth maps from the U.S. Federal Reserve that illustrate the subprime mortgage crisis. From the press release:

The maps, which are maintained by the Federal Reserve Bank of New York, will display regional variation in the condition of securitized, owner-occupied subprime, and alt-A mortgage loans. The maps and data can be used to assist in the identification of existing and potential foreclosure hotspots. This may assist community groups, which can mobilize resources to bring financial counseling and other resources to at-risk homeowners. Policymakers can also use the maps and data to develop plans to lessen the direct and spillover impacts that delinquencies and foreclosures may have on local economies. Local governments may use the data and maps to prioritize the expenditure of their resources for these efforts.

To be updated monthly; only data for December 2007 is currently available. Thanks to August for the link.