LONDON — Don't get Steve Howe started about Las Vegas.

"Oh, the climate! I didn't see a cloud all week!" he exclaimed, driving around London in a pink taxi with "Las Vegas" emblazoned in huge letters down the side. Ever since the gambling mecca's tourist board brought him for a visit, his friends have called him "Steve Vegas," one of a growing number of London cabbies hired to be word-of-mouth ambassadors for foreign destinations.

More than a quarter of London's 25,000 licensed taxis now carry advertising across their hoods and doors, selling a variety of products and places, from pizza to the state of Mississippi. The city's iconic black taxis are increasingly not black, and more of them are being driven by people trained in what marketers call the "spiel at the wheel."

"Drivers are never going to keep their mouth shut — that is what London cabbies do," said Andre Coetzee, general manager at Taxi Media advertising. "We capitalize on that."

Asher Moses, managing director of Taxi Promotions UK, which arranges for U.S. destinations to be splashed across this city's taxis, said drivers are ideally suited for promotion. After all, he said, they have a "captive audience" for about 16 minutes — the average length of a London cab ride.

GUSHING ABOUT VEGAS

In Howe's taxi, passengers can practically feel the heat off the neon of the Las Vegas Strip as he drives through the cold midwinter rain. The dream catcher dangling from his mirror is from a Nevada Indian reservation, he explained, before gushing about Vegas hotels "so big it takes 10 to 15 minutes to walk past them."

"Some people don't want to talk, and that is fine. It's up to them," said Howe, 51. "But often the first question people ask is: 'Have you been to Vegas?' "

Then Howe can describe the penthouse with a Jacuzzi where he stayed, plus the shows, the casinos and the "big portions of food that we are not used to."

"It's a great idea," said Allison Raskansky, Las Vegas-based director of marketing for Grand Canyon West. "There is nothing like someone who has been there, who's had a good time and telling others to go."

The chatty-cabbie marketing plan has raised eyebrows among government regulators, who say they worry that the drivers are infringing on a passenger's right to peace and quiet. But even as a spokeswoman for the Public Carriage Office said officials would remind drivers that they are not to serve as "advertising agents," she acknowledged that nobody had complained yet.

Selling America to British tourists these days is like selling half-price water to the thirsty. With the British pound now worth about $2, the United States has become Britain's bargain basement. Time Out magazine, Britain's most popular guide to how to spend the weekend, last week featured shopping in New York on its cover.

People on an average salary in Britain are snapping up houses in Florida. They are spending weekends in Manhattan grinning over price tags in dollars.

EXOTIC U.S. SITES

In fact, so many British travelers go to the United States — about 4 million a year — that they are increasingly seeking out what are considered here to be more exotic U.S. destinations. Mississippi, Tennessee and the Great Lakes are among the places now advertising on London taxis.

"We are seeing growth in more rural areas, even places like Kansas City," said Stella Clery-Ackland, managing director of Cellet Travel Services Ltd., a marketing and public relations company that represents Utah, Missouri and other states.

She said British travelers like bed-and-breakfasts, and on the Internet they find charming ones that lure them "to real America, small-town America, where there has been a resurgence in travel."

She said older British people are traveling, too. "Before, grandpa might be content to sit at home with his pipe and slippers," she said, but now he is interested, for instance, in riding a Mississippi riverboat.

Terry Bateman, who like many London taxi drivers owns his own vehicle, has turned his shiny new $70,000 black London cab a watery blue to advertise the Great Lakes. For that, he said, he earns about $2,000 a year, helping him pay the high price of gasoline, which costs twice as much as it does in the United States. Bateman said passengers inquire about the Great Lakes, with many simply asking, "Where are they?"

The Web site displayed on the taxi and printed on Bateman's receipts (greatlakesnorthamerica .co.uk) describes the freshwater lakes as a region "the size of continental Europe."

But Colin Casey's taxi needs no explanation: It advertises the city of Memphis, with a huge picture of Elvis on one side and one of B.B. King on the other.

"People say London's taxis should be black," Casey said, and that is why he didn't want just any old color or ad on his roomy vehicle.

"People love Elvis. Someone is always taking photos of my taxi," said Casey, who was married by an Elvis impersonator in Las Vegas.

Those who have been drinking, he said, even start singing "Hound Dog" or "Blue Suede Shoes."