SAN DIEGO -- Hundreds of pop culture and comics enthusiasts lined up outside of the San Diego Convention Center today for the opening of the star- studded Comic-Con International convention.

The sold-out Comic-Con is the hottest ticket in town, with more than 125,000 people expected to attend the convention during its four-day run, which will feature hundreds of exhibits, celebrity appearances, film screenings and industry panels.

On tap Thursday is a panel discussion featuring film director James Cameron -- along with actors Sigourney Weaver and Sam Worthington and producer John Landau -- to discuss his upcoming alien-planet saga "Avatar." The film is Cameron's first full-fledged film project since the wildly successful 1997 blockbuster "Titanic."

Cast members from the film "The Twilight Saga: New Moon," the sequel to last year's box office hit "Twilight," will answer questions from attendees and show never-before-seen footage. Among those rumored to attend is the star of the films, Robert Pattinson.

Later this week, Jamie Hyneman and Adam Savage will discuss their show "MythBusters"; Seth McFarlane will take questions on his series "Family Guy"; and "The Simpsons" creator Matt Groening and David X. Cohen will discuss whether the animated series "Futurama" will return.

Peter Jackson, the filmmaker behind "The Lord of the Rings" trilogy and "King Kong" remake, will attend Comic-Con for the first time to support TriStar Picture's "District 9."

Film directors Robert Zemeckis and Tim Burton will make appearances, as will science fiction and fantasy author Ray Bradbury; Steve Epting, the artist behind "Captain America" and "Avengers"; veteran voice artist June Foray ("The Rocky and Bullwinkle Show"); and MAD magazine cartoonist Sergio Aragones.

Danny DeVito, Robert Downey Jr., Woody Harrelson and Jennifer Love Hewitt are among numerous Hollywood stars rumored to be attending this year's convention to promote new films and television shows.

The 35th annual Comic-Con "Masquerade" extravaganza will be held on Saturday, featuring a costume contest, stage shows, presentations, simulated battles and displays on four large video screens.

Over it's 40 year history, Comic-Con has grown from being a haven for geeks to a mega-event that draws Hollywood heavies promoting the latest films and television shows.

The event began in 1970 with a one-day convention at the U.S. Grant Hotel in downtown, featuring monster writer Forrest J. Ackerman and science fiction writer Jack Kirby as the first guests.

The convention runs from 9:30 a.m. to 7 p.m. today through Saturday, and 9:30 a.m. to 5 p.m. on Sunday.