Star Wars, because he had ideas for visual effects in his head that hadn't yet been invented.
At the time, special effects were used almost exclusively to create scenes with monsters and space ships and explosions (and the very cool twister in The Wizard of Oz), and were still fairly rudimentary in how they were made and filmed.
But as the technology became more advanced, including CG (computer graphics), the movie industry realized that visual effects could be used to much more subtle effect.
"At one point in Forrest Gump, he's playing ping pong and he's playing at this phenomenal speed. You might ask, 'How did Tom Hanks learn how to play ping pong?' Well, the answer of course is, he doesn't. He's just moving the paddle, and somebody's putting the ball in....
So it's this simple little thing, but what it meant was the story point would go into movie and the audience doesn't know or care about it. And we reached that point where it's not about special effects any more. It's about telling the story."
~ Ed Catmull, director, Lucasfilm Computer Division 1979-1986
In the documentary, Ed and other ILM veterans talk about the CG team being able to manipulate the sky to get the kind of shot they wish they had photographed. You see Gary Sinise's legs literally being erased for the character of Lieutenant Dan. And you see the ridiculously skillful ping pong matches played by Forrest Gump that, when the movie came out, astounded many of us.
Visual effects have grown up. They can just as easily be applied to comedy, drama, science fiction and adventure movies. They enhance many genres of film, not just action. As Samuel L. Jackson says in the documentary,
"We're all jaded when we go to movies. We watch all kinds of stuff that we aren't supposed to be looking for. We're looking for the seams, we're looking for the cracks. But when they make you forget all that and pull you into the magic that is the story, then they've succeeded."
If you're using PowerPoint or other slideware in your presentations, then you are using visual effects. But in most presentations, we are not going for Star Wars- or Jurassic Park-style effects. Nor are we aiming for effects that have no purpose or benefit to the scene.
We are going more for the kinds of effects that subtly add clouds or a sunset to a plain sky to enhance the mood of a scene, or remove a character's legs to make his war injuries appear more realistic.
"...It's not about special effects.... It's about telling the story."
Ask yourself if your slides are too dramatic for your presentation. (Your special effects are taking over and you're becoming an action film.) Ask yourself if your slides are superfluous and unnecessary for your presentation. (Some presentations don't need special effects at all, like documentaries.)
When your visuals are the perfect enhancement, adding to the story, but not becoming the story, then you are using your visuals properly. George Lucas would be proud.