Above is the price-to-rent ratio (Case-Schiller). Q1/97=1:1; you can see that home prices took off (broke the typical range) at the very end of 2001. Housing prices will continue to fall (or rents may rise) for a while--likely another 3-4 quarters.
In another chart, Calculated Risk shows Case-Schiller for Chicago and Minneapolis housing prices. They've dropped 12% and 17%, respectively, from their peaks; whereas Charlotte and Dallas are only off by about 4%.