I've read some science fiction stories and some technology speculation where people predict that our future homes, offices and everything is a computer touch screen. Our desks, our walls, our ceilings and floors, public spaces and private ones too. It seems to me that they usually assume this will be done by making touch screen computers thinner, cheaper and as easy to apply as paint.
I wonder, though, whether you could do it today with projectors and gesture recognition. To turn every surface in a home into a touch screen, you'd just mount projectors to the ceiling. Point them everywhere, and use a system like the Kinect to track people and gestures. They'd be like light fittings. This strikes me as a better idea than trying to build in or attach a touch screen monitor to every surface.
Mokalus of Borg
PS - Though still very expensive with today's technology.
PPS - And not especially private.