That was the scene Friday afternoon outside the MGM Grand Garden arena, where several thousand fight fans lined up to watch boxers Floyd "Pretty Boy" Mayweather Jr. and Oscar "Golden Boy" De La Hoya weigh in for their super welterweight title match in the same arena tonight.

The fight, projected to be the largest grossing event in boxing history, is one of several events contributing to the buzz, and ka-ching, this weekend in Las Vegas.

The boxing match alone is expected to generate more than $12 million in nongaming spending by the 16,700 fans in the arena. That doesn't count people who came to Las Vegas sans tickets with the hope of getting close to the action. Nor does it include spending by Cinco de Mayo revelers or Kentucky Derby bettors, two other excuses for tourists to party, gamble and spend money.

"This is the first time we ever came to an event like this," said Saul Daniel, 49, of Monterey County, Calif. "This may be Oscar De La Hoya's last fight."

Daniel and several members of his family drove more than seven hours from Northern California to be in Las Vegas for the fight. They stood in line at the MGM Grand clutching souvenir-edition boxing gloves.

The fight buzz, said Daniel's son-in-law Daniel Munoz, 20, is why the family of fight fans came to Las Vegas in person instead of watching it on pay-per-view at home.

"It is a big difference just being here," Munoz said. "It is more exciting."

Whether the confluence of several events will swell the local economy much more than a typical weekend is less obvious than the welterweight fight buzz.

Indeed, the fight attracts big spenders to town, and the Derby will generate lots of betting.

But how much those events will boost visitation traffic over the 275,000 or so tourists who visit Las Vegas on a typical weekend is unknown.

"It doesn't really look like there is any kind of a bump," said Michael Zalatel, operator of the hotel-booking Web site i4Vegas.com. "We actually sold more last weekend."

Zalatel's Web site and several others still had rooms available for the weekend as late as Friday afternoon at dozens of hotels, including popular resorts like MGM Grand and Luxor.

At the Las Vegas Hilton resort operators will capitalize on the Derby by promoting their race and sports book and bringing in their best casino customers for private race-watching parties, said Jay Kornegay, executive director of the Hilton race and sports book.

"It is such a big weekend especially for the sports books," Kornegay said.

He expected the 300-seat sports book to be standing-room-only for the horse race on today and forecast another 500 people at the private Derby party.

Kornegay said the horse race alone could generate about $30 million in wagering statewide, compared to nearly $100 million for the Super Bowl.

"The electricity in the room right now is unbelievable," he said. "If there is one race they are going to bet it will be the Kentucky Derby."

Robert Tuchman of TSE Sports & Entertainment, a New York City-based firm that books luxury trips to the Super Bowl, NASCAR races and other special events, said he has about 120 clients in Las Vegas for the fight.

Some of them will be in seats that cost more than $10,000, said Tuchman, president of TSE.

They are also likely to spend more per person than the $750 the Las Vegas Convention and Visitors Authority estimates a typical tourist drops on nongambling activity during a visit, Tuchman said.

"Most of the guys we are bringing are executives who obviously have the money to blow," said Tuchman, whose clients stay in swanky hotels like Wynn Las Vegas, Bellagio and MGM Grand.

But Tuchman questioned whether boxing would survive as a top-tier draw for Las Vegas. He said the Mayweather vs. De La Hoya event is the hottest boxing match in five years but he doesn't anticipate many similar fights with the same cachet in the immediate future.

UFC fighting, a style that uses octagon-shaped cages and allows fighters to kick, punch and hold, is rising in popularity while boxing fades, Tuchman said.

"I think UFC is a better draw than boxing," he said. "We are getting a lot of corporate interest in UFC as it becomes more mainstream."