LEXINGTON, ALA.: Picture the Manhattan skyline filled with Nike swooshes. Or the golden arches of McDonald's gently drifting over Los Angeles.

A special-effects entrepreneur from Alabama has come up with a way to fill the sky with foamy clouds as big as four feet across and shaped like corporate logos — ''Flogos,'' as he calls them.

Francisco Guerra, who's also a former magician, developed a machine that produces tiny bubbles filled with air and a little helium, forms the foam into shapes and pumps them into the sky.

The Walt Disney Co. will use one of the machines next month to send clouds shaped like Mickey Mouse heads into the air at Walt Disney World in Orlando, Fla., Guerra said.

''It's a shock factor when you look up and there's a logo over your head,'' said Guerra, whose company, Snowmasters Inc., makes machines that churn out fake snow and foam for Hollywood movies and special events.

He developed Flogos at his small factory in northern Alabama — a perfect place for research and development, he said, partly because there aren't many people around to ask questions about the foam shapes that float above the building on test days.

A Flogo machine works a little like a Play-Doh Fun Factory, the $5 toy kids use to squeeze colorful putty into stars, circles and other shapes.

A boxlike contraption produces a specially formulated white foam in a big round tub and forces it upward through a stencil. Once the foam is several inches thick, a metal cutter slices it and a faux cloud floats into the sky.

''You want some wind because you want them to travel,'' Guerra said. ''If there's no wind they just spiral upward slowly. We've got a ghost [stencil], and on a calm day it looks like everyone is going to heaven.''

Guerra's company is working on a version that will spit out 6-foot clouds.

The foam is environmentally safe because it's mostly water, air and a soapy agent that creates bubbles, Guerra says. Flogos pop just like bubbles and disappear when they hit a tree or building, sometimes leaving a powdery residue that blows away.

A single Flogo can travel as far as 30 miles and as high as 20,000 feet, Guerra says, and a machine can produce one every 15 seconds. Guerra says he could put a half-dozen machines together and fill the sky with almost any shape a company orders.

Imagine a line of drifting Flogos shaped like the Honda
logo leading to a car dealership and you get the idea.

A professor who specializes in environmental issues and public policy said Flogos didn't sound like a pollution hazard if they're really just specially formulated soap and water.

''It sounds like it's harmless, but there's a lot of stuff that we thought was harmless that turned out not to be,'' said Jerry Emison, a professor of political science and public administration at Mississippi State University.

Kathleen Bergen, a spokeswoman for the Federal Aviation Administration in Atlanta, said she had not dealt with the company before but it appears Flogos would fall under FAA rules pertaining to events like balloon launches. She said a local FAA office would need to be contacted before a Flogo launch so that pilots could be notified about it.

The company has lined up international distributors in Australia, Germany, Mexico and Singapore. A machine rents for about $3,500 a day, Guerra said.

Matt Leible of New York-based Generation Outdoor, an ad agency specializing in outdoor advertising, said companies can spend $5,000 a day for a big banner with graphics towed by an airplane, and skywriting can cost $4,500.

Want to rent a blimp? That's $250,000 a month, and companies typically want a six-month minimum, Leible said.

James Twitchell, a professor of English and advertising at the University of Florida, compared Flogos to airplanes pulling banners over football games, spotlights with corporate logos and an old imagined scheme to put an advertisement into orbit that would be visible at sunset.

''It's been done before. Well, kind of,'' Twitchell said.

One expert said the idea sounds catchy, but wonders how Flogos will fare against a backdrop of controlled airspace, environmental sensitivity and concerns over legal liability in case something goes wrong, like a pilot being distracted by a swarm of floating tomahawks above an Atlanta Braves game.

''I think people will look at them. The question is what happens after people look at them,'' said Leonard M. Lodish, a marketing professor at the Wharton School of the University of Pennsylvania.

Only a few people have seen Flogos so far, including a crowd at the local ballpark one day when the company was testing. There was no way to ignore the test clouds as they floated lazily overhead, said Augie Hendershot, police chief in Lexington.

''Everybody thought it was neat,'' he said.