Hundreds of people walked into an Irish pub in New York City on July 24, swarmed around the jukebox and began chirping like birds. Within five minutes, the crowd had disappeared completely, exiting the bar just as quickly as they had appeared. Was it some sort of strange new club dedicated to bringing the music of birds to the general public? Perhaps it was some sort of prohibition-type movement to scare patrons out of bars?

No, the jukebox incident was just the latest spectacle in a fast-growing trend known as “flash mobs.”

Part performance art, part surprise party and mostly just for fun, flash mobs are socially organized events meant to confuse and bewilder the general public, usually organized using cell phones, pagers and e-mails.

Originally created by a mysterious individual known only as “Bill from New York,” flash mobs came into existence this past summer and have already been spotted everywhere from San Francisco to Minneapolis and even as far as Europe.

Bill first began the flash mob craze by e-mailing 50 friends to gather at a retail store in downtown Manhattan. The plan was foiled when store employees were tipped off by an anonymous source, but the group quickly reorganized to mob a Macy’s department store across town.

Out of the clear blue, more than 100 people crowded onto Macy’s home-furnishing floor and began discussing whether to purchase a “love rug” for their fictitious commune. Then, to the confusion of the Macy’s staff, the group completely disappeared leaving the employees to wonder if it ever even happened.

Just this sort of reaction, utter bewilderment and mass confusion, was the initial purpose of flash mobs from day one.

Flash mobbers are usually highly secretive concerning the details of their plans in order to increase chances their events will be successful. “Scott,” a member of the Yahoo! Milwaukee-based flash mob group “brewcitymob,” agreed to be interviewed under the condition he be identified by first name only.

Scott admitted that he joined the group to see “the reaction on other peoples faces when out of nowhere a ton of people show up and do something that is usually pretty funny.”

“It’s all just to shock people,” Scott said, “But in a good way, ya know?”

Though the phenomenon was originally started as a form of amusement, many businesses are now trying to use the popularity of the flash mob to create free advertising.

Linda Gorchels, director of the executive marketing program for the University of Wisconsin business school, has noticed a growing number of fashion-focused companies using flash mobs for publicity purposes.

“It’s usually done with teenage clothing companies,” Gorchels said. “That’s an industry that is more influenced by peer pressure, so the use of large crowds of people around products is more effective.”

Gorchels, however, expresses some apprehension about the marketing trend.

“On a personal level, I have some concerns about whether or not companies are manipulating the results,” Gorchels continued, “but as far as whether or not it could work, I think it probably could.”

Flash-mob popularity is increasing by the day and 91 groups have already registered on Yahoo! groups as flash-mob focused. Those interested in participating in a flash mob can go to www.flashmob.com or www.mobproject.com for more information.