I don’t know whether we really need this when we have multiple monitors and really wide screens, but such an idea could find a market somewhere out there.
IDEs do a lot of amazing things already. Now, check out Beryl and Compiz Fusion. When you will have a glove mouse, a keyboard+Joystick, or a “Linux Cheery Mouse” ;-), you will really want to 3D-ify your coding environment. As the business of selling technology products essentially constitutes selling the feature pieced over multiple versions, as a first step, you could introduce into your IDE a slide-sorter view like in presentation software.
The thing should come up as Alt+Tab and should show you the functions used in the code in the alt tab switcher in an adjustable-zoom thumbnail view. Then the whole thing will look like this:
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Whaddaya say?
Take two steps back 