This was inspired by Minecraft, and the very end of this video
http://www.youtube.com/watch?v=QYWG4nAnOGo

I am currently reading up on better lighting techniques in CGI, I have been pretty okay with lighting so far, but I figured it would be a good thing to read up on proven techniques and then go from there. So I bought this book "digital Lighting & Rendering" written by Jeremy Birn (a Lighting Technical Director at Pixar) and I can say it is a very good read so far.
Even though amazingly I seem to have come up with a lot of the commonly used techniques on my own so far, I could have saved some time if I had had this book 10 years ago.

The cave model for this picture was done in about 2 minutes, it's really just a squashed sphere with a dent in the top and some distortion. Some of you might notice the even geometric topology.
But I took my time with the lighting and it took me about 1 hours to set up and another hour I spend tweaking stuff that didn't need tweaking. But the result should speak for itself.
This light setup uses only standard lights, most of them without shadows. I used no automated light system like Global Illumination so this renders pretty quickly. I am going to make more use of this in future animations. (if I can convince myself that I am not rendering another preview)

Wallpapers sizes:
1024x768 - 1280x960 - 1280x1024 - 1600x1200