Audiences who catch Johnny Knoxville and cast performing outrageous stunts in the just-released Jackass: The Movie might wonder where all the professional fall guys have gone.

They wouldn't be alone. With the advent of digital effects and more actors doing their own stunts, some speculate that stuntmen might dive right off the silver screen.

"One of the weird things that's happened with special effects is that they've really diminished the role of stuntmen," said Charles Taylor, a contributing writer and movie critic at Salon.com. "More and more people are making the decision to just fake it."

Others predict the stunt industry is here to stay, but believe its role is evolving.

"I don't believe that new technology is going to kill our jobs," said 20-year veteran stuntman Keii Johnston, 39. "It's going to change our jobs, but I think the two can complement each other."

Johnston, a vice president of the Stuntmen's Association of Motion Pictures who doubled actor Bruce Willis for a decade, said he frequently hears filmgoers complaining about movies too reliant on digital effects.

"I've heard many times, 'Boy, that looked really fake,'" he said. "They want to see the real deal."

Some film gurus seem to agree, saying computerized stunts are noticeable and distracting. The heavily digital Spider-Man was panned by movie critics like Roger Ebert, who said the superhero-flying sequences and other effects looked cartoonish. Box-office audiences didn't necessarily agree, however, and made the film a huge hit.

"I don't really mind stunts being done digitally because it makes it more fantastic," said film buff Chien Hwang, 32, an advertising art director in New York. "You understand why they have to do it. Sometimes it's not feasible to get real people."

In fact, most of today's film stunts are a blend of digital effects and human feats. In scenes where a building explodes, for instance, stuntmen might stand in front of a green screen and be jerked by cables, reacting to the invisible blast -- footage of which is actually superimposed later.

Fans of James Bond movies are anxiously awaiting the November release of the latest installment, Die Another Day, to see if it will reach new Bond action-sequence heights by combining digital effects and stunt work -- or even by going all-out digital.

A movie like Paramount/MTV Pictures' Jackass -- where the crazy stunts are real and bound to be controversial because of copycats and injury potential -- could reinforce the need for stuntmen. At least one of the zany guys in the movie was hurt during filming, according to E!.

Though the Jackass cast members aren't actors -- and the on-set injuries weren't serious enough to affect filming -- studios generally prefer to use professionals instead of actors for the trickiest scenes.

"If you have a stunt sequence that has the possibility of really hurting your main star, why would you do that? You'd let the stunt double do it," Johnston said. "If an actor gets hurt on the set, the movie is done. I don't think we're going to be replaced by actors."

Actors like Angelina Jolie in Lara Croft: Tomb Raider and Tom Cruise in Minority Report are giving their own stunts a try. But even then, said Johnston, stuntmen still need to be on set to teach the stars.

"It's done very safely, rehearsed over and over again with the stunt double," he said.

Johnston said technology has actually helped make some stunt work safer. The use of decelerators, cables and ratchets, for example, means falls are done more securely than in the old days, when stuntmen were hurled off platforms with more primitive machinery.

At the same time, he said, it's also made filming riskier stunts possible.

"We can now be on a 1,000-foot building and do a 100-foot decelerator fall," Johnston said. "Because of audiences wanting to see bigger, better things, the industry has always pushed those limits. Today's technology will push them even further."