Levitating helicopters? Wheels rotating contrary to the vehicle motion? You probably have seen it in movies, video, or on television. These are not special effects, but rather a natural consequence of unavoidable aliasing when recording video.
See a video of a levitating helicopter and an analysis of the aliasing that led to this "special" effect at Aliasing in Movies: Levitating Helicopters and Wheels Rotating Contrary to Motion.