I posted earlier about the idea of virtual daylighting and it looks like someone has gone and actually done something about it.
"one innovative designer is experimenting with LED lights to create fake sunlight reflections on interior walls. Using over 3,000 LED lights, which give off the natural color of sunlight, Daniel Rybakken is designing lighting fixtures in the shapes of parallelograms, which give the impression of sunlight coming in through a window and reflecting off a surface.
Before, the entrance was a dark, dank, scary sort of place, and afterwards, with the white walls and reflecting light on the stairwell, you’d think they had added windows and a skylight. This light shift makes a huge difference on the psyche and even though all you see is a distorted rectangle light reflection, it looks exactly the way actual sunlight would reflect in through a window on a wall. "