Computers are marvelous. They can do incredibly boring, repetitive tasks such as arithmetic and transfers of data at unbelievable speeds and they can automate all sorts of useful tasks. None of this does any good to anyone, though, without some sort of input and output system, in a way that a car with no doors or a toaster with no bread slots would be useless in the extreme.
The ways in which humans can interact with modern electrical computers have evolved considerably, from the days of mechanical typewriter-based outputs and punch cards to more modern keyboards, mice, and multi-touch input systems with graphical interfaces. With the Leap Motion, we can add a new dimension of input, both literally and figuratively, but we need to decide how to let users issue commands via hand motions and how to have our software translate the gestures into useful input and respond accordingly.
This task is somewhat complicated with a lack of a shared understanding or vocabulary among end-users...