A new trend, called "flash mobs" are usually organized over the internet. But a pulitzer prize winning cartoonist is behind this one.

What is a flash mob? Here are a few examples. In New York, a mob of people suddenly showed up at a toy store to worship a dinosaur then disappear. In Seattle, a party erupted at Pacific Place Mall. Minutes later the revellers were gone.

A flash mob is usually arranged through mass e-mail for a quick public thrill.

But cartoonist Gary Trudeau was behind this one.

In Monday's Doonesbury comic strip, the character "Alex" typed: Saturday, September 13th, 10:35 a.m,. at the foot of the Space Needle. Everyone should link arms in an enormous circle, hop up and down, chanting "The Doctor is In."

"It's a flash mob for Dean," Alex explained in the strip.

The reference is to Howard Dean, M.D. and Democratic candidate for President.

"I'm a Howard Dean supporter, and I read Doonesbury. I was going to come to Seattle anyway, and I read that comic on Monday and thought, '10:35? why not,'" said Jacob Metcalf at the base of the Needle.

Roughly 100 other people thought the same thing, and right on cue at 10:35...."The doctor is in! The doctor in! The doctor is in!" they chanted.

It lasted less than minute.

"The fact that it just started because of a comic strip is funny," said Brent Youngren, who brought his son to participate.

"It was just for fun," added Christine Edger.

And just like that the fun was over. The Space Needle was back to normal. All in a flash.