That's simply not true, although alot of people believe that because movies are 24fps. But then again, movies use a special techinique (forgot what it's called) to make it seem as if the video is real smooth, by blending images together or something. (If you stop a video where the camera is moving very fast, you will notice the picture being blurred, because the lens was open for too long a time, but ofcourse, you don't notice this if the movie is actually playing.)
There was once a screening of a 60 FPS movie somewhere at a futuristic themepark in France, and according to eye-witnesses, it was most remarkable. Really realistic.
Besides, even in games you can notice a clear difference between 24 FPS and 60 FPS. Although, like Raze said, anything above 60 doesn't make a difference anymore.
Tovi 