Superheroes, fringe artists, Hollywood stars, pin-up girls and storm troopers all came together over the weekend for a teeming cultural stew at this year’s WonderCon convention.

The show was held in the Moscone Center in downtown San Francisco, where last year 18,000 people showed up to preview upcoming movies, meet with prominent comics artists and show off their hand-made costumes. Many exhibitors and attendees said this year's turnout was even bigger.

Exhibitors on the main floor ranged from comic shops and publishers to the Suicide Girls and San Francisco's Asian Art Museum. Retailers offered a wide range of wares: samurai swords, video games, out-of-print toys and CDs, original artwork from famous artists, signings and sketches. Some journalists covering the convention spotted musician Tom Waits walking around with a “Hellboy” art book under his arm.

Guests walked the floor dressed as “Star Wars” characters and superheroes; one man wore a full-length xenomorph costume from the "Aliens" movies.

"I wouldn't dress up like that myself, but it's a lot of fun to watch," said Mindy Owens, 24, a liberal studies major at SF State.

Chris Richards, dressed as Boba Fett from "The Empire Strikes Back," came together with the 501st Legion, an organization that brings together costumers and “Star Wars” fans.

"There's definitely something [about WonderCon] –– you could call it a buzz," Richards said. "You walk around and people stop and ask you if they can take your picture. You take on an air of celebrity. You know, you go about your daily life like everyone else, but at the show you almost become [the character]. It's the biggest rush, and you know your hard work is appreciated."

Above the bustling, crowded exhibitor floor, several conference rooms hosted about 80 different panel discussions over the course of the weekend. Subjects included the roles of women as characters and creators in comics, how-to costuming discussions, promotional panels from several major comics publishers, and Hollywood advance promotions and screenings.

Director Brad Bird was there to discuss "Ratatouille," his new film with Pixar, and preview new footage of the movie along with the picture's star voice actor, comedian Patton Oswalt. The film will be about a rat in Paris with a burning passion for creating fine food that teams up with an inept bottom-rung kitchen worker who desperately needs to hang on to his job.

"We're thinking of renaming it “Ratatouille 1,” and letting you guys know it's the prequel to the sequel," Bird joked, pointing out the film will come out in the summer alongside movies like "Spider-Man 3," "Indiana Jones 4" and a second "Aliens vs. Predator" movie.

"It's the fifth ‘Alien’ versus the third ‘Predator,’ but the sequel to that," Bird said.

Another film previewed was the upcoming action flick "300." Director Zack Snyder and star Gerard Butler attended the screening and took questions from the audience.

"It was kinda creepy how much the girls were falling all over [Butler]," Owens said. "One girl kept going on and on about how she thought he looked like Elvis."

Writer Jeph Loeb got his own panel for an hour, which he largely used to field questions about his comics work and his involvement in television shows like "Lost," "Smallville" and "Heroes." He used the opportunity also to talk about the Sam Loeb College Scholarship Fund, which he founded after his son, Sam, died of cancer in June 2005, at the age of 17.

The foundation annually gives $10,000 to a graduating student at Sam's high school, North Hollywood High, but with no strings attached –– the money can be used for anything.

"They can use it to buy a car, or throw the world's greatest party, or pay for housing," Loeb said.

"There's no application. You can't fill out a form. The teachers and I select someone we think has Sam's qualities, someone who's brilliant and funny, and has a healthy disrespect for authority," Loeb said.

Back downstairs, models from the Suicide Girls Web site –– known for its pin-up photography of pierced and tattooed women –– chatted with guests and sold clothing and magazines.

"This is kind of our target market: guys who are on the Internet a lot," joked photographer Taye Lore. "Actually, it's been a pretty even mix of guys and girls coming up to talk. Everybody likes pretty girls."

WonderCon is one of three annual conventions put on by San Diego Comic-Con. Its other shows include the eponymous San Diego Comic-Con International, the biggest comic-related convention in the United States, and the Alternative Press Expo (or APE), held for independent comic artists every April in San Francisco.

Image Comics, a large Berkeley-based comic publisher known for pushing creator-owned work, kept a booth right in the middle of the WonderCon floor for all three days.

"WonderCon's great," said Mark Britt, Image's director of marketing. "It's got the diversity of San Diego, but it also has a strong local feel. It's a high volume show, but there's enough space here for everyone to mingle together."