On this Labor Day, a time to honor the working men and women who make this nation's job machine churn, you might want to take a special moment to think of people like Martha Huerta.

In her eight-hour shift at the ABC Diaper Service in Berkeley, she sifts thousands of diapers, one by one, her hands sheathed in yellow gloves and a fan taped to a shelf near her head to blow away the stench.

The diapers come fresh from myriad baby bottoms, slathered with the colorful result that parents know so well. Huerta, 27 and the mother of three, is lightning quick as she flings each cloth through an electronic counting machine -- about one every two seconds -- but the truckloads are never-ending.

In a year, her hands will touch more than 5 million diapers. From her, they go to a Volkswagen Bug-sized washing machine that rocks them in a 160-degree brew of suds and bleach before they are shipped back out on a route that eventually leads them back to Huerta.

``Sometimes the goopy stuff falls on your shoes or on the floor, but I just use another diaper to pick it up, and then I move on,'' Huerta said one morning last week as she sorted. Asked if she enjoyed her task, she and one of her managers, Sandra Munoz, both chuckled.

``This is a very good job, and someone has to do it,'' Huerta said, smiling. She's had her job five years.

``She's great, and she's strong,'' added Munoz. ``And I think it helps that her sense of smell isn't very good.''

Similarly distinctive people answer other singular career calls: Artificially inseminating farm animals, sucking in car fumes while collecting bridge tolls, sitting inside a locked, hot booth at a self- service gas station, carving at a slaughterhouse, putting down puppies at a pound.

We're talking about life's nasty jobs, the drudgery-laden, usually low-paying tasks that must be done but that would send most people fleeing. The men and women who do them don't just need a can-do attitude -- they need can-do fortitude. Ask them if they truly like what they do and you'll usually get a laugh or the sort of look reserved for the tax man. A paycheck, benefits, and the satisfaction of pulling one's weight are the main draws.

Most of these folks do their jobs with gusto.

Take those who must masturbate turkeys to ensure that America's Thanksgiving tables and sandwiches stay well- filled.

Most turkey farms have genetically bred birds whose juicy breast meat sections are so big they cannot mate -- so the job must be done by human hand, start to finish, said Dr. Francine Bradley, an avian scientist at the University of California at Davis. And because turkeys are notoriously ferocious when improperly aroused, workers must be unusually focused, skilled and gentle as they stroke the males from neck to genitals and inject the ejaculate into the females.

``You have to develop a relationship with your tom (male), and the turkeys really come to prefer certain people,'' said Bradley, who has trained people in the tricky craft. ``It's not easy work, very dusty and sometimes dangerous. I once had a student pick up a turkey without heeding my warnings, and the bird flapped a wing so angrily it broke one of the student's arms.''

Kirsten Spalding, a University of California at Berkeley employment researcher, said it is not surprising that workers in such jobs are content to hoe their gritty rows.

``Stable jobs are disappearing, even unskilled jobs like janitorial work,'' said Spalding, a labor policy specialist at the campus' Institute of Industrial Relations. ``A lot of companies are using temporary agencies instead of employing their own workers so, increasingly, any job that offers benefits and pensions is looking more and more attractive.''

Robert Hill never fooled himself that taking bridge tolls would be a thrill. But compared with what he did before he took his post in a tiny Bay Bridge toll plaza booth nine years ago, it sometimes seems downright relaxing.

``I turned a wrench on a General Motors assembly line, and believe me, this reminds you of that a lot -- but at least it's outdoors,'' said Hill, a 57-year-old with nimble hands and a ready grin for the 4,000 or so drivers who pass beside him each day. In the time it took to make that statement, he plucked dollar bills from three drivers and punched a counter button three times.

``You do the same thing over and over and over and over, and yeah, it gets dull,'' Hill said, never missing a beat. ``The trick is to have a radio with some rhythm and blues, and try to not think about anything -- and I mean anything -- while you do the work.''

Hill's booth, one of 20 at the plaza, is barely big enough for his chair and a counter-cash box console. Throughout his shift he gets plenty of returned smiles, but he also endures the occasional curse or insult. And once in a while, something weird happens.

``Funny thing, but in the summer and right around Halloween, I get a lot of people coming through here having sex in their cars,'' he said. ``They'll pull right up to my booth and look at me like I'm supposed to be surprised. I just say, `Where's your dollar?' ''

At least his job is safe. Plenty that pay little are not.

A survey this summer by the National Institute for Occupational Safety and Health found that the job in which you are most likely to be slain in America is taxicab driver. Deputies and police officers take up the second- and third- deadliest spots, but notching in at a close No. 4 is gas station worker.

That comes as no surprise to Tony Ngyen, who spends the hours from 1 to 11 p.m. each day, seven days a week, locked into a booth at the Spartan Gas self-serve station at 10th and Taylor streets in San Jose. It's a somewhat seedy stretch of road where tough lowriders rule the night, and Ngyen is under orders not to venture beyond his glassed-in chair.

``I've never been robbed, but it happens,'' said Ngyen, 36, during one hot, stuffy shift last week. ``I think the worst part of this job is just sitting. I bring every different book I can every single day, otherwise I'd go out of my mind.''

Ngyen, a Vietnamese immigrant, said that nonetheless he's glad to have a steady, ``above-minimum-wage'' paycheck. If he could change just one thing, it would be to end the racial insults regularly hurled his way. ``Good thing I'm behind this thick window,'' he said.

Not quite so lucky was Vanessa, the former manager of a check- cashing counter in downtown Oakland.

Her profession is also known for stickups and rough customers, but she hung with it for about a decade for the steady pay. Then came the time in 1993 when thieves frustrated by the bullet- proof glass smashed a hole in the ceiling and slid down a rope, handcuffed her to a toilet and emptied the safe.

``Then the next year a guy put a knife to one of my workers' necks and made me let him in,'' said Vanessa, who asked that her full name or that of her former employer not be used. ``He left when he couldn't get in the safe, and he was so mad I thought he'd kill us.

``The real kicker, though, was when my boss got abusive when I told him I wanted better security. He told me I was just trying to be lazy and to waste his money.''

She quit.