Sure, okudagrams are cool, so those eye-widening futuristic GUIs found in many of those movies with ever-bleeping annoying computers. Pure eye candy: they make no sense and you won't ever find such a thing in real life.
Just in case you need for your project to show a computer (or tablet, or cell phone) with a realistic looking interface in its display, with its windows, buttons, menus, and so on, you may like to know there's a free prototyping tool used by professionals: the Pencil Project. It lets you design your interface screen and export it as a image file you can apply to the computer in your movie project. BTW, it comes with other assets such as a good deal of assorted shapes and flowchart components which can be used also in your mockup.