To put into perspective: How much had home values dropped in United States?

We've heard how bad the economy is in the United States, and that home values had dropped lower than their mortgage loans, thus foreclosures are happening everywhere. Just how much had their value dropped?

Now we're car guys, and we have no idea how the housing or real estate market works, but generally most of us would've been familiar with the concept of still owing, say $15,000 on our car loan's hire purchase, whereas our cars might just fetch around $11,000 in the market. Small issue right?

How about houses in the US? Just to put into perspective, which should not be a benchmark used against the board:

A 1,000 sq ft home with three bed rooms and 2 bathrooms costs around the price of a Toyota Camry in the USA now.

The same home costs around the price of an Astom Martin V8 Vantage 5 years back.