Picture a muggy summer day in New York City. A man known only as “Bill” sends e-mails and cellular phone text-messages to about 100 people. State-of-the-art technology is utilized as his message races through fiber optics wires and invisibly through the air, allowing all of the contacts to receive his message mere seconds after he has sent it.

The message? Synchronized instructions to meet at a highly populated public place in order to commit a major act.

Starting to sound like the next big terrorist attack? Maybe. But it’s definitely not what it seems. That day two months ago was the first recorded occurrence of a social phenomenon known as flash mobbing. Their public act? To gather in Macy’s, admire a $10,000 Oriental rug, and explain to the baffled salesman that they belonged to a commune and were seeking a “Love Rug.”

Thus began this summer’s biggest, and least reported, fad.

Since then, flashmobs have become famous worldwide; they’re the flagpole sitting of the new millennium. The objective is always the same: Show up at some public place. Do something absolutely pointless. Leave. Make sure you have fun.

Over 100 strangers participated in the New York practical joke, all under the command of an anonymous leader. They came out of nowhere and left just as quickly. And now people from all over the world are doing it.

The explosion was rapid. Within two months, countless flashmobs were organized in the United States, Asia, and Europe. Websites sprouted up. Some, like mobproject.com, just report on them; while others like flocksmart.com are international databases through which organizers can establish flashmobs in their city and regularly post mob updates.

It’s impossible to know how many flashmobs exist or in how many cities; but mobs are estimated in the hundreds, members in the high thousands. These could be considered cells, each completely functional with no central leadership. Sound familiar?

With little to no media coverage, word of mouth alone is responsible for the popularity explosion. And it’s largely Internet word of mouth.

Since Bill’s first mob, thousands of copycats have joined in the fun, but chances are you’ll see it before you hear about it.

Crowds have played Marco Polo in Dallas, shouted “yes” into phones in Berlin, and formed human chains in Zurich.

In Cambridge, Mass., over 200 people flocked into a greeting card section of a store; each person asking the salespeople to help them look for a card for their “friend.” His name? Bill.

It’s all been very undisruptive. So far.

It doesn’t take the most devious person in the world to imagine the power behind this seemingly harmless fad. The tremendous advantages of anonymous organization through broadband and wireless Internet have been forced into the public eye, and damaging deeds from small-time vandalism to massive terrorist attacks could be the next step.

Plans could be sent instantly to dedicated followers who carry out some task, having little or no knowledge or pre-meditation of their job, making it extremely difficult to discover the plots before-hand.

Conversely, there are no limitations to the good this could bring. Political protests could be organized in hours. Volunteer groups could form instantly to help in the event of a disaster. Thanks to Bill and his friends, everyone knows how easy it is, and the possibilities are boundless.

Once again, technology is changing the world around us before our very eyes, and it’s impossible to tell, as always, what these new changes mean for us as we move onward, into the future.