Read it here (NY Times). Much has been made lately of the apparent bubble in housing in certain areas of the country. As a measure of that bubble, we can look at the price-rent ratio. Calculated Risk, for one, has been keeping track of it. The Times article indicates that the tide might be turning, at least in some areas.
Throughout the South, in cities like Atlanta and Charlotte, N.C., fewer apartments are empty, building managers say. Nationwide, the vacancy rate for rentals fell to 9.8 percent in the second quarter after having climbed early in 2004 to 10.4 percent, the highest level since the Census Bureau began keeping statistics in 1956.
That might reverse the trend that I noted here.

Anecdotally, rents here are going up fast (having two kids in college makes you aware). Some rental agencies are even refusing to take anyone without a rental history...so there are non-monetary price aspects as well that the staistics may not pick up.
The other thing that might play a role is the point that multiple unit housing starts have been flat since 1997.
The other thing that is hard to understand is the sharp drop in mobile home shipments over the past 5 years. Does it reflect the point that rents were cheap?
Spencer,
On multiple unit housing, I made a similar point over at EconLog.
http://econlog.econlib.org/archives/2005/08/housing_rents_a.html
You might have a point on the mobile home market. I'm not familiar enough with the data or other particulars of that market to say so with any certainty.