The Case-Shiller Home Price Indices data through August 2008 shows "continued broad based declines in the prices of existing single family homes across the United States, a trend that prevailed throughout the first half of 2008 and has continued into the second half."
Nine of the 20 regions have record annual declines. Phoenix and Las Vegas are now returning -30.7% and -30.6% versus August 2007, respectively. Each of the California markets- Los Angeles, San Francisco, and San Diego- are down more than 25% from their values 12 months ago. Miami and Tampa, the two Florida markets, are down 28.1% and 18.1%, respectively.
August 2008 Home Price Index
table via TFS Derivatives
National Trend of Home Price Declines Continues into the Second Half of 2008
S&P, October 208, 2008