Lights ... Camera ... Obsession!

Three years ago, Julie Wright spotted a bumper sticker with a quote from one of her favorite movies, "The Big Lebowski." On it was a Web address for LebowskiFest.com.

"I went and checked it out and I saw that there was this whole culture about this movie," says Ms. Wright, who wore an official festival bowling shirt to this year's Lebowski Fest – the third she's attended.

Wright, like thousands of other fans, has stumbled upon one of Louisville's most unlikely events – a gathering that celebrates the 1998 Coen Brothers cult classic. In the offbeat comedy, "The Dude" (Jeff Bridges), a Los Angeles slacker whose only passion in life is bowling, gets sucked into a bizarre kidnapping mystery.

In Louisville, that mystery has been translated into a festival that includes concerts, costume contests, trivia challenges – and, most important, bowling.

Some might argue that a festival for "The Big Lebowski" is decidedly more cool than, say, a "Star Trek" convention, but it's still a public expression of deep involvement in a fan community. In the past, openly admitting such fandom – especially if one is serious enough to attend conventions – would have been akin to pinning a scarlet F on your chest. But these days, experts say fan culture for television and movies is more pervasive than ever. Thanks to the Internet, previously closeted fans can network with their counterparts around the world, building strong communities unafraid to celebrate their shared loves.

"[Twenty years ago] the cliché was that fans lived in their parents' basement," says Dr. Jenkins, a leading authority on fan cultures and the director of the Massachusetts Institute of Technology's Comparative Media Studies Program. Now, he argues, "fandom has become so pervasive in our culture that there are relatively few people who at one time or another in the course of their lives don't engage in fandom community practices."

All around the world, fans aren't just watching movies or TV – they're building complex social networks centered around films, television shows, and books.

For instance, the town of Preston, Idaho, plays host to the Napoleon Dynamite Festival every year. In fact, organizers estimate that the film was responsible for 500 new families moving to the city. The fan club for the 1980 Christopher Reeve time travel love story, "Somewhere in Time," organizes an annual October gathering in Michigan at the film's setting: Mackinac Island's Grand Hotel. In Australia, a touring "Blues Brothers" band performs music from the 1980 John Belushi and Dan Aykroyd film.

Jenkins attributes the boom in fan culture largely to the Web, which empowers aficionados to network and exchange ideas. Indeed, untold numbers of cult-movie discussion boards or MySpace tribute pages span cyberspace and allow fans to connect in unprecedented ways.

The Lebowski convention, however, started off-line. Six years ago, two friends selling posters at an extreme tattoo and piercing convention in Kentucky began quoting lines from "The Big Lebowski" to pass the time. Other vendors joined in and began to bond.

At that point, Will Russell and Scott Shuffitt had a revelation. "If they can have this tattoo convention, why can't we have a Lebowski convention?" says Mr. Russell, who peppers his speech with phrases and the lingo of "The Big Lebowski."

So Russell and Mr. Shuffitt decided to organize a Lebowski Fest in their hometown of Louisville, a locale that has nothing to do with the film. The duo expected 20 friends at the first fest in 2002. They were thrilled when 150 people showed up.

Compelled to make the event a tradition, the two created a website for the festival and unbeknownst to them, Spin, a popular music magazine, listed the event in their annual calendar. Attendance at the next festival jumped to 1,200 people from over 35 states, says Russell. They've since hosted Lebowski Fests in New York, Las Vegas, and Los Angeles (the latter included a visit from The Dude himself, Jeff Bridges). They even ventured abroad to England and Scotland. But they plan to keep the main event in Louisville.

While science-fiction movies like "Star Wars" can build fan cultures around the fantasy element, films about everyday life, or at least not set in outer space, often attract disciples because their protagonists aren't traditional heroes.

"For people in our culture, it's not always Tom Cruise and Bruce Willis who get their motor running. It's people like them," says Peter Exline, a film professor at the University of Southern California in Los Angeles who inadvertently inspired the Coen Brothers' creation of "The Big Lebowski." "They're drawn in by the attitude that [characters like Napoleon Dynamite and The Dude] have toward the conventional, materialistic, success-driven world."

Lounging on the lawn outside the Executive Strike and Spare bowling alley, home to this year's sixth annual Lebowski Fest, Pat O'Keeffe says, "There are people who get it and people who don't." On the flight to Louisville, Mr. O'Keeffe, who traveled to the event from Lancaster, Pa., with his 15-year-old son, Jack, says that people unaware of the festival approached him and his son to talk about the movie when they spotted the duo's "Big Lebowski" T-shirts.

"It's a gathering of like-minded people," says Tom Esterline. From his well-used headband and utility vest to the coffee-can-turned-make-shift-urn, Mr. Esterline, veteran of seven Lebowski Fests, looks convincingly like Walter Sobchak (John Goodman). The landscaper says that an appreciation of "laziness" – the defining characteristic of The Dude – is the common trait that bonds Lebowski die-hards.

As participatory fan networks develop, they sometimes take the values espoused in their favorite text and try to use them in the real world. For Stephen Asthon, who performs as "Elwood" in a Blues Brothers tribute band in Tasmania, Australia, his love of the film goes beyond its entertainment value. The plot begins when a nun dispatches Jake and Elwood Blues to raise money for their childhood orphanage. Staying true to that spirit, Mr. Ashton's band performs at least two concerts a year to benefit children's charities.

"It's not just re-creating the music from the movie and that sort of era," says Ashton in his thick Australian accent, which he keeps even when performing as Elwood, a native Chicagoan. "We try to keep the same passion and what the movie was all about."

A segment of J.K. Rowlings fans have taken on an even more ambitious agenda for social change with the Harry Potter Alliance (HPA). "Did you ever wish that Harry Potter was real? Well, it kind of is. After all, both our worlds face 'dark and difficult times,' " says the HPA website.

The fan group draws parallels between issues and events in the book series and major political issues currently facing the real world – genocide, discrimination, global warming, poverty, torture, and more. "[T]he HP Alliance is dedicated to bringing together Harry Potter fans from everywhere to spread love and fight the Dark Arts in the real world," explains the group's website.

Professor Jenkins from MIT argues that the way fans engage a film or text has provided something of a model for how they become involved in politics. "These are very interesting moments where the world of participatory culture is starting to blur over into the world of participatory democracy," says Jenkins.

Back at Lebowski Fest, while fans are decidedly apolitical, many have embraced one of the movie's catch phrases as a way to make it through the turbulent times: The Dude Abides.