Trends and fads are generational. The hippie movement died with Watergate. Disco ruled, until it became a bad word. MTV once dictated popular culture; now it airs Jersey Shore.

But geeks and nerds? They’re forever — and their ranks are growing.

In Comic-Con Episode IV: A Fan’s Hope, one of the films screening Thursday through Sunday during O Cinema’s Comic Book Movie Weekend in Wynwood, director Morgan Spurlock ( Super Size Me) follows several attendees to the 2010 San Diego Comic-Con — the largest nerd mecca in North America — as they pursue dreams of drawing superheroes for a living, winning elaborate costume contests, or tracking down prized collectibles.

Not so long ago, their passionate, sometimes quixotic quests — like one man’s frenzied hunt for an 18-inch Galactus doll — might have been written off as trivial pursuits.

Today, though, everyone is paying attention.

“There was a time when nerds were guys who sat around on their computers and geeks were the ones who read comic books and action figures, and everyone made fun of them,” Spurlock says. “But now, those two worlds — geeks and nerds — have collided, and today they control every aspect of the media and the entertainment business. Geeks and nerds are the ones who are creating those tablets we’re using to read, the iPods we’re listening to, the movies and TV shows we watch, the books we read. These people who were once seen as fringe and weird have become incredibly influential. And now you see frat guys wearing Green Lantern T-shirts. It’s almost become a badge of honor to show you’re an adult who still embraces your childhood passions and has a sense of play in your life.”

Evidence of a nerd-friendly culture abounds. On Sunday, The Avengers broke box office records by grossing an astonishing $200 million in its initial three days of release in the U.S. (its worldwide tally stands at $642 million). Due later this summer: a 3D reboot of The Amazing Spider-Man and The Dark Knight Rises, Christopher Nolan’s final entry in his trilogy of Batman films.

The prevailing acceptance of all things geek transcends superhero movies. On HBO, the medieval fantasy Game of Thrones — based on George R.R. Martin’s perennial bestsellers — is drawing nearly 4 million viewers per week, despite having been dismissed by The New York Times as fodder for “Dungeons & Dragons types.” A Game of Thrones videogame is due May 15.

The Elder Scrolls V: Skyrim, another videogame released last November in which players slay dragons and perform magic, generated $620 million in its first month of sales. Other past and present cultural phenomena - the Harry Potter series, The Lord of the Rings, Twilight, The Hunger Games – have proven there’s a healthy appetite for geek fodder around the world.

More than any other genre, fantasy has benefited from the advent of CGI and special effects technology, which have revolutionized the way movies are made.

“More people are embracing nerd culture because so much of it is so good,” says Michael Avila of AviLand Productions, a content provider for SyFy.com and other entertainment websites. “If they had tried to make Game of Thrones a decade ago, it would have had the production values of Xena: Warrior Princess. There were several Marvel movies made in the 1970s and ’80s, but they were terrible. Gradually, though, the budgets got higher and the talent pools got deeper.”