Western tourists -- brimming with confidence and cash -- make tantalizing targets to professional con artists, who pride themselves on preying upon their victim's vulnerability, be it lust, greed, confusion, gullibility, or hubris. Other scammers dispense with trickery altogether, relying on threats or thuggery or a modern-day Mickey Finn. Since an encounter with one of these bad-will ambassadors can wreck your vacation, we skulked around the world's back alleys, taverns, and tourist traps, to root out the latest rackets.

Russia. Visiting Moscow can be an enriching experience -- especially for local crooks. Tourists arriving by air must declare how much currency they are bringing into the country if it's above a certain threshold, roughly $1,000. Once travelers leave Moscow's airport, a pair of uniformed customs officials turn up, asking to count your money again. He then runs off, leaving the tourist burdened by bags, laptop, etc. Adding insult to injury, the second officer points out that chasing the thief would leave the tourist's bags unattended, a liability in a crime-ridden city like Moscow.

France. Gangs of "art students" in Montmartre have been known to block tourists meandering through narrow alleys in the medieval town and implore them to sit for portraits. While briefly chatting with the imposing painters, one of the students will immortalize the mark in pastel chalk and angrily demand $100 per drawing. "The sketches looked like something my 8-year-old nephew could have done much better," recalled one recent victim, who paid up rather than risk retribution from Monet's Mafia.

Cambodia. In Phnom Penh, where young prostitutes are rife as "genuine artifacts" from the Angkor Wat, less scrupulous strumpets give guests at the city's few decent hotels more than they bargained for. Before the seminal transaction, the pro lets it slip that she's new to the business, perhaps a virgin. After the trick she leaves, only to return early the next morning escorted by her "cousin," usually a huge, scowling rent-a-thug. They barge into the room, present the groggy whore-monger with a positive pregnancy test, and demand a cash settlement of several hundred dollars. In this time-honored hustle, the "I wore a condom" excuse wears thin.

Singapore. According to The Straits Times, imposter bellmen shrouded in stolen uniforms have been known to rip off guests' passports at Singapore's fancier hotels, including The Mandarin and Orchard Parade Hotel. These well-mannered "employees" apologize for disturbing their marks before asking to borrow their passports for just a few minutes. The story goes that the hotel needs a photocopy of the document for their records. International smugglers buy the pilfered passports for several thousand dollars each.

Columbia. Touts who peddle hash on the beaches around San Andreas Island also sell information to corrupt local police, according to Robert Young Pelton, author of The World's Most Dangerous Places. Beach bums finger clients to cops, who later bust down the door of the mark's hotel room and cart stoned tourists off to jail. To win their freedom, marks must pony up bribes, as well as the cost of meals consumed while in stir. Those are the lucky ones. The U.S. State Department warns that foreigners arrested for possession of even small amounts of narcotics in South America routinely can face judicial delays of between two- to four- years in prison awaiting trial.

Tunisia. In the souks of Tunis, hustlers hawk "Roman" coins and oil lamps that were supposedly filched by workers on an archaeological dig. To create the illusion that you've got a real steal, the fence mentions that exporting artifacts out of Tunisia is illegal. Don't worry about a long sentence in desert prison though; the goods are fakes with a patina finish achieved when the "craftsman" urinates on the items and leaves them to dry in the sun.

India. "Professional ear doctors" receive patients on the streets of tourist ghettos like Goa. These faux physicians thrust laminated certificates into a tourist's hand, and prescribe an immediate ear canal cleaning for every malady. While the mark studies the fake ID, Vijay Welby M.D. rams a Q-Tip or a metal implement into their target's ear, producing a shockingly massive wad of wax. The doc demands a hefty fee for the "cleaning," while chiding the startled Westerner for his or her poor hygiene.

Greece. Traditionally, most tavernas in Greece allow patrons to pick the fish that they intend to eat. The government sets the price per kilo, but some restaurant owners run fishy businesses, grossly overestimating the weight of the selection. Ask the price of a fish before ordering, since it's difficult to prove your case once the evidence has been digested.

Czech Republic. Counterfeit cops prowl the streets of Prague, wearing uniforms, badges, and even nightsticks. Typically, the pretend police turn up to "arrest" money changers at the moment they strike a deal with tourists. The bogus cops seize the cash, and in exchange, hand back a receipt for evidence, which is redeemable for little but a hearty laugh from authentic officers of the law.

Peru. In some Lima bars, one drink can be one too many. Robbers soften up tourists by lacing cocktails with burundanga, a tasteless yellow powder containing the drug scopolamine. Forget a hangover! The powerful potion induces disorientation, vision loss, hallucinations, a dry mouth, and memory loss. Ben Box, editor of the South American Handbook, recommends that barflies watch bartenders unseal bottles of booze.

Brazil. On arrival at Rio's airport, some taxi drivers show passengers an official-looking list. Column A displays well-known hotel names, and column B lists corresponding prices in local currency. The taxi driver will try to charge these amounts, which are actually nightly room rates.

Italy. Scamming can be a crappy business -- literally. Some thieves splatter feces on their horrified victims. Their partner -- posing as a Good Samaritan helps to clean off the mess -- while helping themselves to your wallet or handbag.