Whose heart doesn't beat a little faster at the thought of getting something for nothing -- even if it is something not really wanted or needed? Who hasn't, while strolling a street fair, picked up hats or key chains or Frisbees emblazoned with the name of some radio station or brand of beer -- only to stash this loot in the back of a closet, never to be seen again? Who hasn't gotten an extra sack of oranges at the supermarket -- as if we're ever going to finish the first sack -- just because they're two for the price of one?

Most of us are what you might call opportunistic freeloaders -- we nibble on samples at the supermarket, save the free address labels we get in the mail. We take what comes to us, in other words -- and that's about it.

But some more enthusiastic freeloaders track down freebies like carnivores stalking prey -- scanning the papers for deals, watching TV commercials with pen and paper at the ready to jot down 800 numbers, and sending away for each and every thing they might possibly want. These are the people with more "trial size" bottles in their bathroom than in a typical drugstore. With more informational videos on prescription drugs than videotapes of favorite reruns of "Seinfeld." With more promotional mouse pads than Bill Gates.

"It's very strange and yet magical that you (can) get so many different things for free," says Carol Southard, a Long Island housewife and dedicated freebie fan who says her daily trips to the mailbox make her feel as though it's "Christmas every day. . . . There is always a surprise."

In the past, dedicated freebie fans shared their tips informally, or through tiny newsletters. But over the last several years, freeloading has gone high-tech: The terminally thrifty have discovered the Internet, and "free stuff" Web pages have begun springing up like worms on the sidewalk after a spring rain. The Yahoo! Web directory lists more than 100 "free stuff" pages (under its Business and Economy heading) -- and that's only the tip of the freebie iceberg.

"I never even knew about all the resources for free stuff before I went on-line," Southard notes in a recent e-mail. "If it was not for the Internet I would not have this strange but wonderful hobby."

At times -- given the immense amount of overlap between the various sites -- it seems as though there might be more free-stuff pages than there are free things on offer.

That's not to say there's any shortage of free offers. As an experiment, I went on-line to see just how much stuff I could request before my hands cramped up from too much pointing and clicking.

Among the spoils after several hours: a "free commemorative sample box" of Kellogg's Smart Start cereal, a 10-minute audiotape titled "Positively You" that "explores some very sensitive questions related to hair loss and replacement," a booklet of moral homilies by William Bennett, a selection of safety posters and booklets (the "Confined Spaces Can Kill" poster looks great on my office wall), some Carbex Synthetic Powder-Free Surgeon Gloves (size 9), a Billy Graham wall calendar (oddly missing January and February), pantyhose, an envelope made of hemp, a Vagistat-1 refrigerator magnet, a cheese recipe booklet from Heluva Good Cheese.

To those not yet bitten with the freebie bug, it might seem like I've requested a lot of junk that I couldn't possibly need. Rationally speaking, that might be true. But rationality has little to do with it: There is something intoxicating about the pursuit of the freebie.

Once you get started, it's easy to find yourself requesting free stuff just for the sake of requesting free stuff. Hence the pantyhose. Hence William Bennett.

"I used to request near everything and anything I could find, simply because it was free," Wendy McElroy, a business student in Victoria, British Columbia, says via e-mail.

Though some freebie fans find it hard to convince others of the joys of their hobby, others report that freebies have become fun for the whole family. "The kids love it," says Southard. "Yesterday I received a coffee mug and a poster. My nephew loves any poster that I get for free and proudly posts them on his wall. And being a coffee-drinking household we can never have too many coffee cups."

For many, the search for free stuff can become all-consuming -- and a few of the more enterprising free-stuff Web masters have even gone pro, lining up sponsors for their pages and collecting income from what began as a private pastime. "I started this as a hobby," says Lee Long, a Baltimore native who runs a Web site called Pumpkin's Freebies. Now it's much more than that. "I spend 12-16 hours a day -- seven days a week -- on the site," Long says by e-mail. "It has become my full-time job, but it is a labor of love."

Of course there's a thin line between love and obsession, as those perfume commercials used to say. "For a while I was so busy keeping up with the Web site I did not have time to even get . . . freebies for myself," says Southard, who has now moved her freebies section off to a corner of Sweetcake's Place, her personal Web site, as a sort of precaution. But she still hunts out the best deals, capping off each day's Web surfing with a request or two for free stuff that catches her eye.

Some freebie fans -- college students in particular -- tend to use their hobby to augment their not-exactly-bulging wallets. "Money is tight," McElroy says, "so every penny saved is of great value."

"My parents had already introduced me to the wonderful world of double coupons, discount stores, and refunds, so free stuff also interested me," says a Rogers Park freebie hunter known on the Net as Datagirl Seven. She doesn't mind that many freebies come in very small packages. "Sample-size toothpastes, pain relievers, shampoos, snacks (and so on) are great for trips," she says. "I can take a few along and if I lose them, use them up, give them away, or don't have room for them in my luggage on the way back, it's OK."

Others are simply in it for the kicks. "I do not buy 50-pound bags of sugar or flour or anything like that," Southard says. "I never ever frequent thrift or secondhand stores. I grew up wearing secondhand stuff, so I never cut corners that far. My husband makes a decent living for us . . . so I don't have a need to cut corners. We own our own house and two cars and have one child in college and still manage pretty well. So I am not really a thrifty person; I just like the thrill of getting something useful for nothing."

What's in it for the companies themselves? Some use the sign-up forms to collect valuable demographic data; others put you on mailing lists.

For larger companies, freebies are just part of the larger project of "branding" -- the sort of relentless promotion intended to imprint a company's name (or slogan, or logo) forever on our brain. If giving away a couple thousand freebies leads a few more impressionable consumers to switch products, it will be well worth it; studies suggest that once consumers "commit" to a particular brand of soda, or mouthwash, or some other everyday product, they stick with it.

Of course, there's always the possibility, however slim, that you'll actually enjoy your free sample enough to buy the product later. "I have found some products that I really like that I would not have tried had I not received a free sample," says Datagirl Seven -- and that's just what the marketers are counting on.

For smaller companies with more specialized product lines, free offers are something of a risk. "Some small companies, not realizing how many people are looking for free stuff and how many Web pages list current offers, are swamped with requests," says Datagirl Seven. For her part, she makes a point of not requesting things she won't use -- "after all, it does cost these companies money to provide these items."

She's not the only one who has adopted a policy of ethical freeloading. "I avoid sending for free stuff that I don't need or have a real interest in, and I encourage my users to follow the same guidelines," says Lee Sears, who maintains a freebie page for The Mining Co., an on-line network of hand-selected special-interest sites. "I view free offers as a limited resource and do not wish to put too heavy a burden on that resource."

Of course, when you're paying nothing for something you can't expect service with a smile. "Sadly, many of the items I request never arrive," Datagirl Seven notes. "The remainder are received up to six months later -- you have to be patient to be a free stuff searcher."

And even the most patient of freebie fans are sometimes less than thrilled by what they finally end up getting. The worst thing Southard ever got, she says, was a home-brewed music video from an unknown band. "The music was horrid and the lyrics I can't repeat and the video itself was disturbing," she recalls. "After one viewing it went right into the trash."

For Sears, the stupidest freebie he ever got was a Cert -- not a roll of Certs, just one measly piece of candy. "They sent this huge envelope," he says, "and the only thing inside was one mint."

Lee Sears' Mining Company Freebies guide: http://freebies.miningco.com/

Sweetcake's Place: http://geocities.datacellar.net/Heartland/9470/index.html

Pumpkin's Freebies: http://www.webspawner.com/users/Pumpkins/