Call them vultures, call them merchants of despair, call them opportunists. They don't care.

They are hooked into one of this year's hottest concepts for small-scale real estate investors in major markets from the west to east coasts: playing Monopoly with foreclosed or "distressed" houses.

You'll find them in droves here in Southern California. You'll find them in Washington, Chicago, Houston, suburban New York, Phoenix and other large metropolitan areas. They don't necessarily want or seek publicity, but they are frank about how and why they are growing so rapidly.

"Look at the national statistics," says Art Groesbeck, president of the Los Angeles-based R.E.O. Institute Inc., one of the country's largest firms specializing in distressed single-family homes and condos:

* The rate of foreclosures has been hovering at or near the records set during the 1973 recession in many markets, according to data compiled by the Mortgage Bankers Association of America. Large numbers of families who bought houses with low-down-payment or adjustable-rate "teaser" loans in 1980 and 1981 ran into economic difficulties in the ensuing recession. They fell behind on their monthly payments and never caught up. Their lenders stopped waiting last year, pulled the plug and took their properties back.

* The Federal Housing Administration and the Veterans Administration -- both barometers of the state of American housing -- are sitting on huge inventories of foreclosed properties. The FHA has approximately 40,000 homes (up from 28,000 in 1983), and the VA took on 30,000 foreclosed homes last year.

* Areas of the country with high rates of unemployment have been hit the hardest by the foreclosure tide, but markets with relatively healthy local economies haven't escaped. Southern California, for example, where razzle-dazzle "creative financing" and balloon loans made real estate an easy buy in the late 1970s, is loaded with distressed condos, investor rental units and single-family homes.

The balloon loans came due, the creative financing fizzled out and the bubble burst -- not only here but in many communities.

"It's often a hidden part of the real estate scene," says Groesbeck. "Lenders don't want to admit how many houses they've made mistakes on. They don't like people to know how much real estate they've got in the closet. And they're often not set up to dispose of their properties quickly."

Groesbeck's firm's name is a direct reference to that hidden closet. "R.E.O." is the lending industry's code word for "real estate-owned," properties reacquired when their mortgages went sour.

In Southern California alone, the R.E.O. Institute has data on more than 2,500 foreclosed single-family homes, condos and "bulk condos" -- chunks of entire buildings that went bad -- all available for sale from lenders at what Groesbeck says are below-appraised-value prices. Many of the units can be acquired for little or no down payment, and they generally come with cut-rate financing terms to boot.

Through contacts with savings and loans, mortgage bankers and institutional lenders, Groesbeck finds out who's got what, where; then he provides detailed lists and descriptions of units to private investors who subscribe to his monthly "REO Realty Registry" (at $150 for a three-month period).

Among the sample listings on a recent edition of the 135-page registry were three-, four- and five-bedroom homes with bank appraisals of $80,000 to $300,000, available to foreclosure investors at discounts as deep as 45 percent. Groesbeck functions as a broker for individual investors in acquiring many of these properties, and he claims that now he negotiates "millions of dollars of R.E.O. purchases each week" between lenders and his clients.

Three thousand miles across the continent, in suburban Washington, an East Coast rival in the real estate distress field is taking out advertisements to push its services. The McLean-based Equity Investment Group Ltd. promises to train "people from all walks of life" to become highly skilled acquirers of distressed houses and commercial properties.

Examples of "typical transactions" that are possible for shrewd investors in the current marketplace include $50,000 to $90,000 homes producing resale gains of anywhere from $15,000 to $30,000 in less than a year's holding, according to Equity Investment. One transaction cited by the firm involved a unit appraised at $94,000 and purchased for $36,800 cash. It sold six months later for $88,800 -- yielding the investor a quick, neat $43,670 capital gain.

Don't get the idea that the skills necessary to pull off distress property killings like this come cheap, however.

The Equity Investment Group will share its special techniques for identifying and acquiring distressed real estate only on the following terms: You pay $7,500 via a certified or cashier's check up front for your initial training. Then you must agree to pay $1,000 to Equity Investment on any purchase in which you realize a "gross profit" of $10,000 or more during the next five years. If you have more than six $10,000 profit transactions in any given year during the next five years, however, you need not pay Equity more than $6,000 during that year.

Total maximum cost for learning how to achieve success through distress? Just $37,500 between now and 1990.