* Hurricane Jimena almost a Category 5 storm
* Hurricane warning issued; winds nearly 155 mph (250 kph)
* OECD moves meeting away from Los Cabos
(Adds fresh tourist quotes; evacuation, storm details)
By Susy Buchanan
LOS CABOS, Mexico, Aug 31 (Reuters) - Hurricane Jimena grew into a highly dangerous storm as it raced toward Mexico's Baja California peninsula on Monday, scaring tourists, prompting residents to sandbag homes and disrupting a top-level finance conference.
Jimena's winds strengthened to nearly 155 mph (250 kph), almost reaching the threshold of a deadly Category 5 storm, the U.S. National Hurricane Center said.
Category 5 hurricanes are the top of the Saffir-Simpson intensity scale and can be devastating if they hit land.
"I've never seen a storm this big in the 23 years I have lived here," said local resident Caterina Acevedo in Los Cabos, a lively resort area at the tip of the peninsula.
"This one is really scary ... but when I tried to leave there were no seats on the planes."
Much of Baja California is sparsely populated desert and mountains that are popular with nature lovers, surfers, sport fishermen and retirees. Los Cabos, which is more built up, attracts tourists to its golf courses, resorts and beaches.
Mexico, a major oil producer, has no oil installations in the Pacific. But ports in the area have started closing due to Jimena, which formed and built up quickly last weekend.
Economy officials from dozens of countries were due to meet in Los Cabos on Tuesday and Wednesday to discuss tax havens, but the Organization for Economic Cooperation and Development moved the talks to Mexico's capital as the storm threat grew.
The meeting was "transferred to Mexico City because of the threat of severe damage posed by Hurricane Jimena," the Paris-based group said in a statement.
Jimena was located about 215 miles (345 km) south of Cabo San Lucas and moving northwest, roughly parallel to the Mexican coastline, at 10 mph (17 kph). Hurricane force winds extended outward up to 45 miles (75 km) from its center.
The Hurricane Center forecast it would hit the Los Cabos area on Tuesday and move inland on Wednesday, dumping 5 to 10 inches (13 to 25 cm) of rain on southern Baja California.
Los Cabos, normally bathed in brilliant sun from dawn to dusk, was overcast and drizzly on Monday.
The port of Cabo San Lucas was shut and a line of trailers formed as yachts, water taxis and glass-bottomed tourist boats were removed from the water for safety reasons.
Colleen Johnson, 55, who just moved down from Canada, stocked up on water, batteries and canned food as she prepared to take shelter. "We're a little leery, but I think we are doing everything right," she said at a Wal-Mart store that had run out of rain ponchos.
Civil protection authorities opened emergency shelters in schools for the area's poorest residents, many of whom live in plywood shacks, but few seemed keen to leave. Empty city buses waited for voluntary evacuees.
Mexico issued a hurricane warning for the area. The Hurricane Center predicted significant coastal flooding and said: "Preparations to protect life and property should be rushed to completion."
Many tourists said they preferred to cut short their vacation than spend two days in a storm shelter.
"I don't want to get stuck here," said Neil Freese, 29, from San Francisco, as he hurried to the airport.
Jimena is the second hurricane of the 2009 eastern Pacific season to brush close to Mexico after Andres pounded the coast in June and swept a fisherman to his death in Acapulco. (Additional reporting by Jason Lange in Los Cabos and Brian Love in Paris; writing by Catherine Bremer)