It's the next step down from flea markets -- an inevitable evolution in a world where the real bargains keep getting harder and harder to find.

It's called junking. Cruising thrift stores, rummage sales, DAV shops and grandma's attic for stuff of questionable character and dubious pedigree. Bottom fishing at the city dump for things serious collectors wouldn't be caught dead with -- like swan vases with plastic flowers, cement yard poodles and seashell-studded lamp shades.

Mary Randolph Carter, vice president of advertising for Polo/Ralph Lauren, spends part of most weekends wandering through junk stores -- the dingier and more downtrodden the better -- from Long Island, N.Y., to Long Beach, Calif. What she finds probably will never turn up in a Ralph Lauren ad. But with a creative touch, a sense of humor and a deep appreciation for the unusual, she manages to transform ordinary eyesores into objects of beauty.

Ms. Carter, author of "American Family Style," has turned her obsession into a new book, "American Junk" (Viking Studio Books). A veritable encyclopedia of trash, it includes hundreds of pictures (taken by Ms. Carter) of fascinating and forgotten stuff, as well as information on where to find it, how much to pay for it and what to do with it once you've got it.

Her own junking odyssey began shortly after college, when she was faced with decorating her first apartment -- a fifth-floor walk-up in New York City.

"I was raised in Virginia and for a big chunk of my life I lived in a 17th-century house," she says. "I've always had a love for older things that had a bit of wear and tear, that had a history, that had something to them."

At the time, she says, she probably didn't think of herself as a "junker."

'Collector's burnout'

"I turned up my nose at thrift shops and was determined to find things at antique shops or antique flea markets." Then about eight years ago, she began to notice that the supply of good stuff was drying up. Antique shops were becoming overpriced and flea markets overcrowded. She began to experience what she describes as "collector's burnout."

The thrill of the chase was gone, Ms. Carter says. "The fun went out of it for me."

"American Junk" was born the day about five years ago when Ms. Carter wandered into the Rummage Shoppe, a converted gas station in Millerton, N.Y. The store was a cornucopia of cast-off treasures -- "from old plastic dishes and pots and pans and pot holders to paint-by-number paintings and old Christmas ornaments." In one box, she discovered a cache of primitive paintings, each priced at about a dollar.

Suddenly, she had an epiphany. "I went, 'Oh, my gosh. I have been looking in all the wrong places.' "

From that day forward, Ms. Carter lowered her sights. Before, she had collected only things that were "acceptable." Now she foraged purely for fun.

"I would screech on the brakes and go into someone's garage or tag sale. I began to frequent places that maybe in the past I thought were just junk. What I found was I could mix some of these odd things, whether it was pink plastic flowers in a blue glass vase, with things that were more substantial. I loved what the junkier, more humorous pieces did to the other stuff. I loved the mix."

For Ms. Carter, junking is intuitive. She never knows exactly what she's looking for until she finds it. Still, she confesses to a weakness for certain things, like:

* Fruits and vegetables: "It started with a strawberry-shaped pitcher. This summer in Nags Head [N.C.] I found another pitcher, clusters of grapes. It's so ugly. Then I realized when I got home, someone had given me a pear pitcher. All of a sudden, I had these fruits. One thing builds on another. . . . I don't know, I seem to be into this fruits and vegetables period."

* Junk masterpieces, including paint-by-number: "I have an abiding passion for paintings -- outsider art. There's something so intriguing about a painting that someone did that was kind of abandoned. Sometimes I see portraits and I'm so moved because it looks like this was somebody's grandmother. How could it end up in this tag sale? I have to take it home and give it a home."

* Wilderness stuff: Moose and deer, antler things, bears. "Whether it's an ashtray with a little bear on it -- I just found a great one in Florida -- or a pillow with an elk on it."

* Western stuff: In upstate New York, Ms. Carter turned a 200-year-old carriage house into a cowgirl's paradise with Beacon blankets, Zane Grey novels, an old Stetson hat, a cast-iron stallion, and "folk-art fakes" torn from magazines and matted with corrugated cardboard.

The great divide

In her book, Ms. Carter divides junk into categories: kitchen junk, glass junk, beach junk, animal junk, etc. She says it helps to have themesin mind before heading out for a day of rummaging. Sometimes, she'll even make a list so she doesn't get distracted. (She also suggests taking along a "junk kit": a magnet for testing metals -- it won't stick to real brass, a small magnifying glass to look for cracks or trademarks, and a Swiss army knife.) Still, she leaves herself open to surprises.

"Sometimes you just see something, like an alarm clock that doesn't work, but it's painted a funny green and you love that green. You love it just as an object. Whether the clock ever works is beside the point."

Unlike expensive antiques, you can't go too far wrong with junk, shesays. "If you say, 'I'm going to spend $25 today,' what do you have to lose? It's not like you're buying this incredible quilt for $300 and it turns out to be a phoney. . . . The thing about junk is it doesn't have any intrinsic value except in the eye of the beholder."

Occasionally, Ms. Carter says, she gets the urge to rid her life of all the clutter. After she and her husband, Howard, bought their country home in upstate New York about five years ago, she began to fantasize about clearing all the junk out of their New York City apartment and leaving just the bare essentials. "I shared this with a few friends of mine and they all laughed in my face.

"I do love clutter and I love hunting for stuff," she admits. "But the thing is, I know if it was all gone tomorrow, it would be OK and I could find it again if I needed to. When I was a child, we lived through a couple of fires. There's something about losing everything that you had to learn how much it was worth or not worth. You realize that other than human life, almost everything is replaceable.

"Maybe in some ways, that's something that I like about junk: It is replaceable. You give it value."

Best places to hunt junk

Author Mary Randolph Carter suggests looking at these places to find good junk:

Pennsylvania

* Renninger's Antique and Farmer's Market, Noble Street, Kutztown, Pa.; (215) 683-6848; 8:30 a.m. to 5 p.m. Saturday

New York

* Sixth Avenue Flea Market, 24th to 27th streets, New York, N.Y.; 9 a.m. to 9 p.m. Saturday-Sunday

* Fish Eddy, 551 Hudson St., New York, N.Y.; (212) 627-8956. Or 6888 Broadway, New York, N.Y.; (212) 420-9020; noon to 7 p.m. daily

* U.S.E.D., 17 Perry St., New York, N.Y.; (212) 627-0730; 12:30 to 8 p.m. daily

Virginia

* Cecil's Antique, 7 W. Broad St., Richmond, Va.; (804) 643-9273; 9:30 a.m. to 5:30 p.m. Monday-Saturday

* Stuckey's Antique Emporium, 315 W. Broad St., Richmond, Va.; (804) 643-4892; 10 a.m. to 5 p.m.Monday-Saturday

North Carolina

* Ponte Antique, 1903 S. Croatan Highway, Kill Devil Hills, N.C.; (919) 441-5757; 9 a.m. to 5 p.m. Monday-Friday; 9 a.m. to 6 p.m. Saturday

* The Twila Zone, 3330 S. Virginia Dare Trail, Nags Head, N.C.; (919) 480-0399; 10:30 a.m. to 5 p.m. Monday-Saturday

Florida

* Douglas Garden Thrift Shop, 5713 N.W. 27th Ave., Miami, Fla.; (305) 635-6753; 8 a.m. to 6 p.m. Monday-Saturday; 10 a.m. to 5 p.m. Sunday

* Vanity Novelty Garden, 918 Lincoln Road, Miami Beach, Fla.; (305) 534-6115; 1 p.m. to 7 p.m. Monday-Saturday

For rummage sales, auctions and flea markets in your area, consult your local Pennysaver or shoppers guide. To find the nearest Pennysaver, call the National Association of Free Community Papers, (312) 644-6610.