PHOENIXVILLE, Pa.—He wore a tinfoil hat decorated with ramen noodle flavor packets. According to the manifesto he carried, the frugal meal had inspired the creation of the hat that protected his brain from evil rays.

Was he crazy? Possibly. He was also a participant in the first-ever Tinfoil Hat Contest at Blob Fest, an annual celebration of the iconic low-budget horror flick The Blob held in Phoenixville, Pa., the Philadelphia suburb where the movie was filmed. Since 2000, people have gathered each year to commemorate The Blob, but this year was going to be special: 2007 marks the 50^th anniversary of the filming of the movie, which was released in 1958.

I've never actually seen The Blob. But I had to go—the campiness and geekiness were too enticing to miss, particularly because, for reasons I'm still fuzzy on, my older brother, Nick, was slated to dance around onstage in a gorilla costume. ("I have an Ivy League education," he reminded me before he crawled onstage.) I even decided to skip a wedding so I could attend. And thank God I did: The reception had a cash bar.

On Friday the 13^th, the Colonial Theatre, an old-timey movie house with a balcony and a single screen, hosted the tinfoil hat and scream contests. What tinfoil hats have to do with the Blob isn't quite clear to me, but the creations were gorgeous—I would happily wear the winning entry if it ever turns out that alien abductees are onto something. As the huge line of hopeful contestants formed for the latter, my ears began to twitch in fear—but luckily, organizers were smart enough to cull a few of the wannabe participants to give us their best shrieks. Earlier in the evening, I chatted with Judy Hennessey, the 2006 scream contest champ. Her advice to the 2007 hopefuls: "You have to be really, really afraid." The winner was a little girl, probably no more than 5, whose screech was so perfect, she must scream often and loudly—or perhaps she was terrified of the drooling albino hunchback character from the New York-based TV show Ghoul a Go-Go who was shepherding the scream contest hopefuls.

Tinfoil hats and screaming are all well and good, but everyone was antsy for the big event: the running out, a re-creation of the picture's most famous scene, in which hordes of moviegoers run screaming from the Colonial to escape the Blob. People inched toward the aisles, hoping to get a head start. This only served to delay the big event—for safety reasons, the running couldn't start till the balcony aisles were cleared. We couldn't start running, anyway: The champion screamer, who was supposed to signal the start of the running, was nowhere to be found.

Once a substitute screamed, I jumped with everyone else into the aisles—only to get stuck behind the mob. No wonder people got eaten by the Blob in the movie. When the congestion cleared, I ran through the back of the theater, through the lobby, out the doors—and was greeted by people holding air-traffic-control wands. As soon as everyone was out of the building, everyone ran toward a man bearing a bucket labeled "THE BLOB." These were the meager remains of the original Blob, and this time—unlike in the movie—everyone rushed to get a glimpse of the once-menacing monster, now just a few handfuls of red-dyed silicone.

On Saturday, the events began in earnest at noon with the fire extinguisher parade—a nod to the movie's ending, when the intrepid teenager played by Steve McQueen realizes that only a fire extinguisher—specifically, a "CO ₂" model, according to McQueen's character—can save the town from destruction. The parade was a bizarre spectacle: A long line of kids and parents marched in a circle, led by a woman in Gypsy garb and a man holding the parade's lone fire extinguisher, as everyone danced to "Beware of the Blob," the movie's poppy theme song (written by Burt Bacharach and Mack David *). Far more inspiring was the costume contest, a testament to what craft supplies, time, and a vivid imagination can produce. My favorite costume was a two-man effort that used giant cardboard cutouts to simulate a woman screaming as she's devoured by the Blob. But the winner was a replica of the Downington Diner, the restaurant the Blob engulfs. Unfortunately, it was so awkward that the wearer couldn't get up and down the steps to accept his prize without assistance.

The vast majority of Blob Fest attendees were Phoenixville-area families, but a small, hard-core group of self-proclaimed Blobologists had come to celebrate all things Blobby—I talked to one couple who drove down from Maine for the occasion. For these people, the highlight was meeting an elderly woman who sat in the lobby of the Colonial signing autographs—Kate Phillips, the screenwriter of The Blob, who earned just $125 for writing one of America's most enduring crappy movies. (At the time, she went by the name Kay Linaker.) I was glad to see her because there was something I wanted to ask. Many Blob Fest attendees suggested the movie was about communism—the giant red mass slowly growing larger and more menacing, swallowing communities. I asked her if that had been on her mind when she was writing, but she scoffed. "I wasn't thinking about communism when I wrote it. I was thinking about good and evil," she said. So much for my attempts to parse hidden meanings from B movies.

Though Phillips might not have intended The Blob to have a political message, she did accidentally insert an environmental warning, which was reflected in the Blob Fest's 2007 theme: "An Inconvenient Blob." I thought it was just an attempt to ride the green bandwagon until I finally caught one of the three weekend screenings of the movie. At the end of the film, the Blob is imprisoned in the Arctic, where, as the narrator menacingly intones, it would remain as long as the North Pole stayed cold. Green activists should add the return of the Blob to the long list of global-warming-related dangers.

Unintentional references to communism and environmentalism aside, there's no reason why The Blob should still be a cultural icon. (I can only hope that Snakes on a Plane isn't being celebrated in this manner 50 years in the future.) But Blob Fest isn't just about a really terrible movie. It's about nostalgia. As almost every local mentioned in our short conversations, in the decades from the filming of The Blob to the 1980s, Phoenixville changed from a safe small town to a place with a serious drug and crime problem—a trend that has reversed with recent gentrification, as evidenced by the kilt store, artisanal cheese maker, and Hipster Home décor shop downtown. Blob Fest celebrates Phoenixville's return to the secure community it once was. Sure, for the horror aficionados, the three screenings of The Blob and the chance to hear movie extras talk about the filming are the big draw. For the rest of the thousands of attendees, it's a chance to take part in hula-hoop contests, listen to a truly awful rockabilly cover band, and bask in the comforting glow of the 1950s. In some ways, it really is what a community fair should be: a celebration of something special about that town. Any place can deep fry a candy bar. Only Phoenixville and the Colonial can do Blob Fest.

Correction, July 24, 2007: This article originally misidentified Burt Bacharach's partner in writing the song "Beware of the Blob." It was Mack David. (Return  to the corrected sentence.)