[thedoc (OP)]

As we build at higher densities, architects are having to think more creatively about how to make the maximum use of natural daylight.
Read a transcript of the interview by clicking here
or [chapter podcast=1000679 track=14.04.29/Naked_Scientists_Show_14.04.29_1002241.mp3] Listen to it now[/chapter] or [download as MP3]

[FunkyWorm]

I worked in a building in the early 90s that had solar-collectors on the roof which fed down via fibre-optic cable to emitters in the ceilings of offices that didn't have exterior windows. It meant you had sunlight in every room.
I once got up on a chair to investigate the 1m sq. "lighting" unit in the ceiling and the best I could see behind the polycarbonate cover was a large Fresnel lens that has the fibre cables terminated behind it. They didn't produce as much light as two mid-length fluorescent tubes but for the most part you didn't need to turn on the lights and it gave a very pleasant feel; the spectrum of the sun being what people like the best. You also got a better feel for the passage of the day and what the weather was like. I'm surprised I haven't seen it in more buildings.

[Ryan Mercer]

I like what they do in developing/'3rd world' nations.... pop bottles and water.

http://www.instructables.com/id/How-to-build-a-SOLAR-BOTTLE-BULB/ [nofollow]  is an instructable on making them

[CliffordK]

Nice soda bottles. 

I've been meaning to install some light tubes and skylights in my house.  Windows are nice.  Of course, there is always a tradeoff between windows and insulation.