Research under way at ORNL could lead to entirely new, highly energy-efficient ways of lighting buildings using the power of sunlight. In addition to providing light, the technology would convert sunlight to electricity much more efficiently than conventional solar technologies. In commercial buildings, lighting consumes more electric energy than any other building end-use. It accounts for more than a third of all electricity consumed for commercial use in the United States.

--This is kinda cool stuff, it uses fiber optics to distribute light from a collector on top of a building to offices below. There is also a video explaining it here: http://www.ornl.gov/sci/hybridlighting/video/hlvideo1.avi

Hybrid Lighting