A picture of a woman’s pink shoe floats on my computer screen. It’s a flat, a street version of a ballet shoe. My job is to categorize the shoe based on a list of basic colors: Is it red, blue, pink, purple, white, green, yellow, multicolored? A description next to it reads “Pink Lemonade Leather.” This is not exactly a brain-busting task; I’m doing it while talking to a friend on the phone. With the mouse, I check a box marked “pink.” In the next split second, a picture of a navy blue shirt appears. I check “blue.” Assuming my answers jibe with those of at least two other people being paid to scrutinize the same pictures, I’ve just earned 4 cents.

With my computer and Internet connection, I have become part of a new global workforce, one of the thousands of anonymous human hands pulling the strings inside of a Web site called Amazon Mechanical Turk. By color-coding the clothing sold by the online retailer, which helps customers to search for, well, pink shoes, I can now call myself a Mechanical Turker. In this new virtual workplace, everything is on a need-to-know basis, including who is doing the work, what the point of the work is and, in some cases, the very identity of the company soliciting the work.

Launched in November 2005, Amazon Mechanical Turk is named after a legendary automaton from the 18th century, “the Turk,” which could play chess. The wooden man, adorned with a turban, appeared to be powered by the machinery of a clock. He even check-mated Benjamin Franklin, a devotee of the game. The Turk was a sensation: a machine that seemed to think. Coinciding with the birth of the Industrial Revolution, the Turk heightened anxieties that machines would replace humans in the workplace. Of course, it turned out to be a fabulous hoax. The ghost in the machine was, as skeptics had suspected, all too human. A chess expert was hidden in the Turk, making all the right moves.

The 21st century twist on the Turk, conceived by Amazon CEO Jeff Bezos, doesn’t try to hide the people inside the machine. On the contrary, it celebrates the fact that we have become part of the machine. For fees ranging from dollars to single pennies per task, workers, who cheekily call themselves “turkers,” do tasks that may be rote, like matching a color to a photograph, but they can confound a computer. Conceived to help Amazon improve its own sites, Mturk.com is now a marketplace where many companies have solicited workers to do everything from transcribing podcasts for 19 cents a minute to writing blog posts for 50 cents. Amazon takes a cut from every task performed.

Amazon claims its virtual workplace provides “artificial artificial intelligence” — a catchy way of saying human thought. “From a philosophical perspective, it’s really turning the traditional computing paradigm on its head,” says Adam Selipsky, vice president of product management and developer relations for Amazon Web Services. “Usually people get help from computers to do tasks. In this case, it is computers getting help from people to do tasks.” As Tim O’Reilly, a computer book publisher and tech industry figure, puts it on his blog, old dreams of artificial intelligence are “being replaced by this new model, in which we are creating more intelligent systems by using humans as components of the application.”

So who wants to be the human component of a computer application? A lot of people, it turns out. Since last November, thousands of workers from the U.S. and more than 100 other countries have performed tasks on Mturk.com. The most dedicated turkers have even formed their own online communities, such as Turker Nation.

The companies are certainly happy. The ones I contacted remarked how stunningly little it costs them to get work done through Amazon Mechanical Turk. Divvying up projects to hundreds of people not only gets the job done more quickly than contracting it out to temps or consultants — much less an actual employee — it gets it done much more cheaply. The tag line for the site could be: dirt-cheap artificial artificial intelligence. One tech company that uses Mturk.com to answer troubleshooting questions brags that it pays tens of dollars on Mechanical Turk for work that would typically cost thousands. And, hey, if companies don’t like the quality of the work they get from turkers, they simply don’t pay them.

As soon as it launched, the Mechanical Turk site sparked a hue and cry in the blogosphere. “Amazon, you cheap bastard. Don’t you at least have the decency to pay minimum wage?” demanded one poster on a tech site. Another commentator sneered that it peddled “jobs even illegal aliens won’t do.” There is something a little disturbing about a billionaire like Bezos dreaming up new ways to get ordinary folk to do work for him for pennies. Is a cut-rate pittance the logical result of tapping into a global workforce of people with a computer, an Internet connection and an Amazon account? And, really, who are all these people working for a measly 1 cent?

The real human ingenuity of Mechanical Turk shines in the novel ways that companies and workers use it to get tasks done efficiently. CastingWords is a transcription service built entirely on the work of Mechanical Turk transcribers and editors. With a little code, plus the turkers, it has succeeded in basically automating the process. The company charges its customers from 42 cents a minute for podcast transcription to 75 cents a minute for other audio. CastingWords pays Mechanical Turk workers as little as 19 cents a minute for transcription. If a transcription job is posted on Mechanical Turk for a couple of hours at the rate of 19 cents a minute, and no worker has taken on the project, the software simply assumes the price is too low and starts raising it.

After a transcription assignment is accepted by a worker, and completed, it goes back out on Mturk.com for quality assurance, where another worker is paid a few cents to verify that it’s a faithful transcript of the audio. Then, the transcript goes back on Mturk.com a third time for editing, and even a fourth time for a quality assurance check. “It’s been terribly useful for us,” says Nathan McFarland of Seattle, one of the co-founders of CastingWords. Transcription is the type of relatively steady task that keeps turkers with good ears who are fast typists coming back. “There are people who have been with us for months, and they’re not leaving,” says McFarland.

One of those workers is Kristy Milland, 27, a mother of one who runs an at-home day care in Toronto, as well as a Web site called RealityBBQ about the reality TV show “Big Brother.” “I have a lot of free time basically sitting at the computer while the kids play,” she says. Among the work she does is editing and quality assurance for CastingWords, but not transcription, because she has tendinitis. When Mturk.com first began, Milland would churn through 3-cent HITs. (That’s “human intelligence tasks,” Turker lingo for jobs.) Amazon was paying turkers to make sure that photos of businesses used on its A9 site, a local search engine, matched the actual businesses listed, a task a computer can’t do. In an eight-hour day, when she didn’t have the kids to watch, Milland could go through 1,000 photos, making a cool $30.

Lately, she’s found a way to goose her earnings by competing for bonuses. A number of service companies use Mechanical Turk to do a “human augmented search.” Say you’re in a sports bar and having an argument about whether Roger Clemens has ever thrown a no-hitter. You can end the debate once and for all with a call to one of the services, which instantly posts the question on Mechanical Turk. Turkers then surf the Web and generally earn 2 cents for each answer.

Back in the sports bar, when you get the answer — “Clemens has never pitched a no-hitter” — you can rate the answer as great, good, lame or junk. Answers deemed “lame” or “junk” are rejected and the worker is not paid. If you don’t rate the answer at all, the worker is automatically paid his or her 2 cents after seven days. Turkers who get the most “great” votes in a week get bonuses of as much as $75. In a good week, Milland can answer 100 research questions, making all of $2, but scoring one of those lucrative performance bonuses, she says, makes the search worthwhile.

The trivia pursuits are so competitive that they’re snatched up by turkers within a minute of being posted. So Milland has set up software to notify her whenever a new question shows up on Mechanical Turk, so she can be the first to grab it. Plus, she’s armed her Web browser with links to her top 100 reference sites so she can answer the questions as efficiently and accurately as possible. Turkers can choose to be paid in Amazon credit, making it easy to shop at the company store. Just the other day, Milland ordered $600 worth of DVDs and books for her family, as well as prizes for contests on her RealityBBQ. “It still doesn’t add up to a lot of money per hour, but if I’m sitting there watching TV anyway, it’s more than I’d make just sitting there,” she says.