Six states — California, Florida, Arizona, Ohio, Michigan and Nevada — accounted for more than 60 percent of all foreclosure activity in the quarter, with California alone making up more than a quarter of all U.S. foreclosure filings.

Detroit and Atlanta were the only cities outside California, Florida, Nevada and Arizona to make RealtyTrac's list of the 20 hardest-hit metropolitan areas.

The combination of sinking home values, tighter mortgage lending criteria and an economy that many economists think has already slipped into recession has left hundreds of thousands of homeowners with few options. Many can't find buyers or owe more than their home is worth and can't refinance into an affordable loan, with the global credit crisis making loans far less available.

For those who can qualify for a loan, or have cash to invest, there are bargains to be had, especially in ravaged markets like Nevada and California. Last month, foreclosure resales accounted for more than half of existing home sales in California, as home sales jumped 65 percent from a year ago, while the statewide median home price fell 34 percent to $283,000, according to MDA DataQuick.

RealtyTrac, however, reported foreclosure filings in September were actually down 12 percent from August. But much of that decline was the result of new state laws that delay the foreclosure process. In California, for example, lenders are now required to contact borrowers at least 30 days before filing a default notice. A similar law in North Carolina gives borrowers an extra 45 days.

Still, that's not likely to be enough to save homeowners who owe more on their mortgages than their homes are worth. Nearly 12 million of the 52 million Americans with a mortgage — that's 23 percent of them — are in that position, according to Moody's Economy.com.

It remains to be seen how much the government's intervention will stem the housing crisis. Earlier this month, the Federal Housing Administration launched a program that aims to prevent foreclosures by allowing homeowners to swap their mortgages for more affordable loans, but only if their lender agrees to take a loss on the initial loan. The bill is projected to help about 400,000 households.

Meanwhile, the Federal Deposit Insurance Corp., which took over IndyMac Bank, based in Pasadena, Calif., over the summer, has been aggressively modifying troubled home loans since August in an effort to stave off foreclosures. Congressional Democrats are calling for that approach to be expanded as the Treasury Department buys billions in troubled mortgage debt as part of a $700 billion financial industry bailout.