What are the all-time movie inventions, those little something specials that over the years have thrilled audiences, padded profits (well, sometimes) and made film historians scratch their heads wondering, now what were they thinking? Let's start with...

Percepto! - For his 1959 infamous thriller The Tingler, moviemaker and gimmick legend William Castle had certain seats installed with a vibrating mechanism, so when "the tingler" (a creature that attaches to your spine) strikes, voila, instant visceral sensation!

Smell-O-Vision! - A one-time only experiment, Smell-O-Vision was the brainchild of producer Michael Todd, Jr., for his feature Scent of Mystery. Three theaters were equipped to deploy various scents throughout the movie to "enhance" the experience. Unfortunately, the cues weren't completely on the mark, making for an unpleasant, thoroughly odiferous affair.

Sensurround! - Basically, the theatrical equivalent to adding a lot of bass to a rock concert. For 1974's Earthquake, theaters went into decibel overload each time a big one shook during the movie. Unfortunately, the effect also caused some of the actual theater ceilings to crack.

Illusion-O! - For William Castle's 1960 horror classic, 13 Ghosts, patrons were handed out glasses that - ta-da!!! - made it so you could actually see the ghosts in the movie. Otherwise, well, you were SOL...

Cinerama! - Why watch one screen, when you can be immersed in a curve that involves three different projectors? That was the logic behind Cinerama, which was used to best effect with the 1962 western How the West Was Won.

IMAX! - Sure, lots of movies are shown in IMAX theaters nowadays, but the best of the best (i.e. - The Dark Knight) actually use IMAX cameras to take full advantage of the incredibly huge IMAX canvases, which are over 70 feet wide and 50 feet tall.

3D! - No film's done it better than James Cameron's Avatar, which has secured its place as the top box office film ever, and has earned enough ooohs and aaahs to make 3D a movie invention that's here to stay for the foreseeable future.