Zillow: US home values to drop about $681B in 2011

Annual loss is 35% less than in 2010

The value of overall homes nationwide has likely dropped just over $681 billion this year, according to property search and valuation site Zillow.

That drop, to a total estimated value of $21.9 trillion for U.S. homes, is 35 percent less than the drop experienced last year, when the nation’s homes lost $1.1 trillion in value.