Decked out in a random assortment of rollerblades, army fatigues, Harvard sweatshirts, nose rings and balloon hats, over 60,000 people attended Central Square's semi-annual World's Fair yesterday afternoon.

The crowd crammed itself along four blocks of Massachusetts Ave. and six side streets to sample a blissfully bewildering assortment of food, wares and music.

"We endorse and encourage creative chaos," said Robert B. Boulrice, head of the Central Square Neighborhood Coalition and one of the initiators of the three-year-old fair. "We're trying to convey that Central Square is a cool place to be, where all sorts of people can come and have a great time."

Volunteer organizers wore shirts sporting the fair's motto: "Celebrating unity and diversity in the heart of Cambridge." And the shirts certainly seemed to fit the occasion.

The 1369 Coffeehouse stand snuggled next to the foot-long hot-dog booth. Vendors of samosas, curry, BBQ and frozen yogurt merrily competed for the attention of passers-by.

The merchandise was no less varied. Central Square stores emptied their insides onto the sidewalk, and merchants came from as far as Vermont to hawk Guatemalan bags and vests, jade statues of Buddha and faberge thimbles (two for five dollars).

"We do this because we're proud of Central Square--we're proud because Central Square reflects the diversity of Cambridge," Boulrice said. "There are over 70 restaurants alone in Central Square, and a vast majority of those restaurants reflect ethnic groups that live in the neighborhood."

More than half of Cambridge's roughly 96,000 residents live in the four neighborhoods adjacent to Central Square. And Central is home to a vast majority of Cambridge's minority population.

Diversity is not simply the goal, it's the rule here.

"This festival is different than a lot of others--you see a lot of people of color here, a lot of different ethnicities--it's terrific," said John Clifford, another of the fair's initiators.

Residents and organizers say the fair is part of the ongoing effort to reverse the image of Central Square, which is sometimes considered an unsafe and uncommercial neighborhood. And, most add, the effort to revitalize the square has been increasingly successful.

"You can't rent space in Central Square anymore on the first floor," Clifford said. "Community outreach has filled up the square with business."

"Central Square is actually becoming much more cohesive, more of a community," said past resident Robert A. Bock, a Harvard graduate student. "Contrary to popular belief, there are mostly young families that live around Central."

"The festival represents more of what Central Square is like," he continued. "There's this misconception that the square is dangerous."

Cambridge residents and students were uniformly positive about the event and about its far-reaching consequences, describing the fair as "awesome" and "delightful." Even the event's organizers seemed to be having a good time.

"It's the third year I've done this, and we always have a blast...You've got great people, great food, great entertainment," said Brendan C. MacDonald, a Cambridge resident and volunteer coordinator.

"But I think the best thing about it is that it's so fun for the kids," he added. "The face painting is free. There's free t-shirt decorating. Nobody says no. Kids get treated right here."

Kids had the run of Essex St., which was packed with trays of toys, cotton candy and bouquets of balloons.

Storytellers and folk dancers wowed sticky children and their tired parents.

Even staid Harvard got in on the act. Students milled around the festival, strolling between the fair's seven stages to hear gospel, reggae, hip hop and salsa.

Those who stayed until the fair's close saw one of Harvard's History and Literature tutors, Edward L. Widmer '84, singing to a crowd of thousands in a wig, velveteen britches and a beauty mark, with his band, "The Upper Crust".

With the Western Avenue stop light swinging uselessly over the stage, eighteenth century noblemen, dreadlocked students and young parents with children perched on their shoulders swayed back and forth to tunes like "Bourgeois" and "Let Them Eat Rock."

Cambridge Mayor Kenneth E. Reeves summed up the afternoon. "I think [the fair] is extraordinary. It's really a snapshot of Cambridge...we have a good time with each other," he said