Thanks for the X10 link. Total news to me. (I already have an X10 receiver that I use, so I am half way there already

That's right, a screw-in light fixture, like a light bulb. I think the glass dome I mentioned earlier will fit well in here, but used upside down (with the wooden base part on top, and a light bulb screw attached to it). We would need to find a way to secure the dome to the wooden base. A small power adapter (the "USB wall wart") should fit in the dome as well. I am thinking that even a glass jar can be adapted for the job, and it would be easier to attach the screw to the metal lid.
A servo will be required to rotate the display (to position it for the best viewing).
Also, a set of high intensity LEDs could be installed opposite to the display matrix, and used as directed, remote-controlable, light source. (now that this Arduino contraption is screwed where the old light fixture was).
I see a few challenges that need to be resolved:
- mic and buzzer are inside the jar/dome/bulb now;
- IR receiver should be reachable by remote even when the whole thing is rotated 180 degrees and not facing the remote (can you have 2 IR receivers in parallel?);
And, listen to this: if an accelerometer is included (or some positioning sensor), then the contraption can be screwed up in the ceiling (hanging down) or screwed down in a desk lamp, and the display will still show the text in the correct stance.
What do you think?