Nui stands outside the bar, well-dressed in black slacks and a dark, skintight button-down. It's his job to attract customers. His counterpart, the unfortunately nicknamed Nut, works inside, dressed seductively in a schoolgirl's uniform. Judging by the number affixed to her chest, it's her job to screw those customers.

Stacked atop each other, Nui and Nut would maybe come up to my chin. Maybe.

Two dwarves, one whorehouse. Welcome to Bangkok's Nana Entertainment Plaza, where fucking midgets is just the beginning.

I'm not here as a customer, but an entrepreneur. In a country where it's cheaper to buy a handjob than a large cappuccino at Starbucks, I'd be a fool not to take advantage of the sex trade. And with Thailand's transsexual katoey more popular than ever, I'd be a fool to waste my time peddling real pussy.

I've come to Bangkok to pimp ladyboys.

Despite being, like, so over in the eyes of pissy backpacking types, Bangkok is still wild around the edges and dirty in its center. Khao San Rd., made famous in Alex Garland's novel The Beach and then the movie, is still crazy mad with scruffy tourists; there's ample opportunity to get laid by chubby white girls.

But c'mon. Think globally, fuck locally.

Everyone else is. You can't walk one city block without seeing a round-eye fattie with a hot woman on his arm. Back home, this man has a thankless job, crippling mortgage payments, a fat-assed wife and a daughter older than his "date".

Here, he's a god. Every afternoon, he eats a meal his wife would normally disallow and slurps down overpriced bottles of Singha, the local beer. As soon as his wrinkled erection is recharged, it's time to find another woman. Since nobody ever accused a sex tourist of originality, he heads to Bangkok's three main prostitution districts.

First, it's the world-renowned Soi Cowboy ("Cowboy Street"), a neon-lit, slut-filled back alley where the tiny stages are crowded with hookers gyrating lazily to pounding dance beats. For fattie to get laid, he simply pays the "bar fine" -- 600 baht is the going rate; that's less than £9 -- then negotiates directly with the girl. A full night of sucking and fucking should run about £21.

Next up is Patpong, a neighborhood famous for matching the simple elegance of the ping-pong ball with the surprising dexterity of the vagina. In bars that smell of liquor, smoke and girl, our fat friend watches those ping-pong balls, plus whistles, candles, even sewing needles -- sewing needles! -- ejected from the closely shaven snatches of Thailand's fairer sex.

Lastly, it's a trip to the Nana Entertainment Plaza at Sukhumvit Soi 4. Don't expect pussy shows here; Nana's three-storey courtyard offers hundreds if not thousands of prostitutes simply sitting at the outdoor bars and grinding on the indoor stages, pulling in the foreigners, or farang, with cleavage and compliments.

And everywhere, the ladyboys may actually outnumber the real women. Every farang swears he can tell the difference -- they talk of cheekbones, jaw lines, hips, Adam's apples -- but I'm not so sure. For my money, voice analysis is the way to go.

When a genuine Thai woman screams for your attention, -- "Helloooooo handsome maaaaaaan!" -- it sounds like a cat being skinned alive. When a katoey bleats out the same greeting, it's the screeching cat and a squealing pig and a set of bagpipes being destroyed in a blender. The katoey caterwaul.

But now, having pimped out my lovely Ae, the most beautiful ladyboy in Bangkok, I don't think you can ever be certain.

Whither the katoey, anyway? Though transvestites and transsexuals are found around the world, Thailand offers more than its fair share.

Some point to the Buddha's famous tolerance. In Theravada Buddhism -- which accounts for 95 percent of the Thai population -- transgenderism is not a sin. Some even say that katoeys were adulturous men in a previous life. Everyone's turning on the same wheel, so it's important to remain compassionate. In the next incarnation, the katoey may be you.

Not all ladyboys are prostitutes, of course. Some are kickboxing legends and professional volleyball players. At least according to two recent movies that broke Thailand's box-office records. Beautiful Boxer tells the story of Nong Toom, the katoey muay thai champion who eventually underwent a sex change and now lives as a woman. In The Iron Ladies (and the sequel, Iron Ladies 2) a team of katoey volleyballers become national champs. Both are based on true stories.

I'm not in Bangkok to hang out with athletes with tits. I'm looking to make cash from an artificial gash.

Nana, I decide, will be my turf.

"What's between your legs?" I ask one particularly scary ladyboy.

"Puuuuuuure puuuuuussssseeeeee."

My friend sends a hand down below. Sure enough he finds a mass of flesh that's "vaguely vagina-like".

No doubt it matches her face, a plastic abomination that's part drag queen, part alien: Angelina Jolie lips, tall forehead, arched eyebrows and acne-scarred skin. One needn't count the chromosomes to know this was once a man.

I ask my question because not every ladyboy has a cock. Not every ladyboy has a vagina. Many katoeys begin popping hormone-rich birth control pills in their teens to soften puberty; some start as early as 10-years-old. That may be the extent of their gender manipulation: tiny little boobs and undeveloped penises tucked up against their assholes.

Others opt for complete sexual reassignment surgery. Fortunately for them, Thailand is one of the world's sex-change centers.

The local surgeons, I'm told, do fine work. After a bilateral orchidectomy ("removal of the testes and spermatic cord"), skin from the cock shaft is used to create a "neovagina"; inner and outer labia are made from the scrotum and other leftover flesh. Nerve endings from the penis head become a clitoris, and the urethra is relocated to the appropriate spot. Even after a tracheal shave and a brow lift, your new woman costs less than a used Lexus.

For an additional $7000, the serious katoey can return six months later for a rectosigmoid colon vaginoplasty. During this procedure, which adds depth and functionality, four to six inches of the colon is used to augment the vaginal canal's depth. According to one doctor, the advantages are twofold:

"The colon vagina had less tendency to shrink comparing to the standard vaginoplasty" and "It is self-lubricated by its own mucus."

A self-lubricating colon vagina -- clearly worth every penny.

My search for a saleable ladyboy takes me to Cascade, up on Nana's third floor, one of several go-go bars trading exclusively in katoey flesh. Here, 20 meat puppets stand on a revolving stage like pies in a restaurant display case. Another 30 work the room, shoving their glistening asses in your face, tweaking your nose, tickling your chin.

Together, they are a bell curve of gender transformation. At one end, bony young men with budding breasts and damning cocks pushing against tiger-stripe bikini bottoms. At the other, voluptuous trannies prettier than your girlfriend.

Honestly, we've all fucked worse.

I hire two girls at 1500 baht (£21) each. The first -- let's call her Bee -- has the standard katoey alien face but she speaks English very well. I hold little hope for a sale; she'll be my translator for the second girl.

Twenty-year-old "Ae" is slim, curvy and young, and has a facial structure that's different than the typical ladyboy's. Wearing a Hello Kitty necklace, tight green shirt and white mini-skirt, she'll pass under any newcomer's ladyboy radar.

She also doesn't speak much English, so I won't have to listen to that katoey caterwaul all night.

Take it from me: If you ever decide to hire a ladyboy, fuck her in the mouth. Not just because vaginas sculpted from eviscerated penises and mucus-lined stretches of colon are scary shit. Anything to shut her up. Really, they're unbearable conversationalists.

"So I guess you don't indulge in the local talent?" I ask a Swede in his mid-50s. He's just refused my girls.

"Sure I do," he answers, "but after four years it gets a little old."

We should all have such problems: banging chicks "gets a little old."

Truth be told, the Swede isn't talking about women; he's referring to the process of whoring. I can appreciate his situation. I've been on this strip just four days and I'm already sick of the sex trade. It's like having ice cream for breakfast every day.

"The girl on the right," I say to Mark, an American English teacher in his mid-20s. "How much would you pay to go home with her?"

"Fifteen hundred, but I'd need to get a room." That means another £3.50, short-term only.

"And another 20 baht for condoms," he adds.

"Any interest in going home with her?" I ask, anxious for a sale.

"No, I'm drained of bodily fluids. I just spent a week in Pattaya."

Goddamn Pattaya. Thailand's most popular resort town, where the sex industry actually puts Bangkok's to shame. If Nana is a simple cesspool, then Pattaya's strip is the neighboring ditch filled with your turds plus aborted fetuses and used jitbags.

The beach to the south can be quite pleasant, though.

Suddenly, I spy a pair of chubby Australians admiring Ae's tight little ass and perfectly pert tits. I ignore the trio of German evangelists holding Bibles and screaming for repentance -- farts in the wind -- and launch into my standard line:

"This is my friend," I say. "She's working with me."

"What do you mean you work with her? What are you, a pimp?"

Finally! A man who understands my valuable service.

I continue: "Around here, you can end up with a ladyboy who knifes you or drugs you. With me, there's no bar fine and you can trust me."

I offer Ae for just 2000 baht, or £28; £42 to double-team her.

The more sober Aussie examines the goods closely, not entirely convinced.

"All girls look alike in the dark," the drunk one urges.

"I've heard that a few times," the friend answers, examining Ae's jaw line. "And I just don't think it's true."

No sale.

Promptly at 1 a.m., the crowd spills out of Nana Entertainment Plaza like seed from a burst condom. It oozes down Soi 4's legs, into its ass crack. The whores are off the clock. Some buy a dinner of grilled chicken feet and fried grasshoppers at the street carts, others go freelance.

The closest I came to reselling my plastic-pussy pals was a one-armed man from Scotland. He wasn't overly concerned with the chromosome count, but was more keen on drinking with his mates. There was also a trio of Turks who would've taken a 3000-baht package deal. But judging from their desperate, angry eyes, my product would've come back damaged.

I pay off my girls, despondent and broke, and wish them good luck. As they run off -- no doubt to find those Turks or the one-armed Scot -- I take a last look at Ae's lovely ass. I consider chasing after her, getting my money's worth.

"Honestly," I think, "we've all fucked worse."