This is what led to the development of these tiny robot Thumbles that roll onto a touchscreen as needed to provide temporary physical controls.
Developed by PattenStudio, a design shop that specializes in interactive experiences, the robots are designed to complement a large touchscreen or projected tabletop interface. Finger taps and hand gestures still remain the prominent way to interact with what's on-screen, but the robots can jump in any time.
So for example, when editing video, one of the robots can hover over the timeline providing a physical way to scrub footage back and forth. Or three of them can roll into position when a color corrector is activated, serving as rotatable red, green, and blue dials.
Because the robots are self-powered, they can even provide force-feedback by rolling against the user's motions. So a slider could be prevented from moving too far, or a dial could provide resistance when a setting is reaching its maximum value. In theory 26 of these robots could form a massive keyboard, although they'd need to be miniaturized even further to provide any kind of touch typing functionality.