I wouldn't mind my whole room to be able to change according to my mood and how I want it that day, like images, colours, anything I want.
Being able to draw in 3d in mid air would also be good, which would be hooked up to something and it could then spin around and be viewed in all angles
Theres something like that coming into play (jus the room bit, not the 3d bit) in Microsofts futuristic house he's made as a tester, and was on a science program not long back.