I'm getting to know my Amazon Echo and although it's
pretty cool, there are obvious uses of it that don't work too
well because its only feedback mechanism is speech.
Sometimes you just need a display - but you don't always
have one handy.
My suggestion is to have a 360 degree projector in
room - either using a pan/tilt mirror (eg a laser projector
projecting upwards from the top of a device like an echo)
or using a hemispherical 360 degree mirror (probably
ceiling-mounted) to have best all-round coverage.
A laser projector would be ideal, because it is always in
The device would have to learn the shape of your room so
that it can projection-map onto interior walls (and other
surfaces) but that's a solvable problem. (Even if it doesn't
use Kinect-like ranging, you could map a room simply by
walking around with a cell-phone camera and a 3D
Then when you need some text info or a diagram it can be
projected onto the nearby wall. It would help a lot if the
device had a camera (especially a kinect-like one) and was
spatially aware of not just the room but the people in it,
so it could choose where to display the info that would be
where you could easily see it.
One implementation of this device could be as something
that includes an LED light, and fits in a ceiling light-bulb
socket, so that it would be easy to add to any room.
This system could also work as an input device by adding a
camera/location sensor - it could project a menu onto a
wall and select items by viewing your hand movements...
(the camera/location sensor is probably needed anyway for
mapping the room surfaces)
Note that an important part of this suggestion is that it can
project onto any wall and that it corrects automatically for
perspective. 360 degree projection and the use of
arbitrary surfaces makes it quite a different thing from
merely using a regular projector pointing at a fixed wall.