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, many of Chicago's western suburbs have taken steep hits from peak pricing levels, but haven't plummeted as far as some of its North Shore suburbs.
The map and data are from Zillow.