The Wall Street Journal has a useful interactive map of home price declines - from peak levels - presented on a map by ZIP Code.
The color-coding on the map instantly makes clear that there's been wide variability in price declines among Chicago's regions and ZIP Codes. That fact helps put the widely-watched Case-Shiller data in a more relevant and realistic perspective. If the data are accurate, North Shore suburbs have taken steep hits from peak pricing levels.
The map and data are from Zillow.