These foreclosure heat maps are very interesting.
Los Angeles (all red!)
SF Bay area (notice that even the Silicon Valley has a lot of red)
Colorado and parts of the midwest
Areas in red mean at least 1 of 600 homes are in foreclosure. Many areas of California have 1 in 150 homes in foreclosure. LA seems especially hard hit (includes the O.C.)
zoom in, zoom out. look in other areas. enjoy.