Hello.
I just stumbled across this page of “lighting challenges”, which provides untextured/unlighted scenes and challenges visitors to finish them.
http://www.3drender.com/challenges/index.htm
It hasn’t been updated for a year, but it might be interesting for those who want to sharpen their rendering skills. And have some other efforts to compare it to.
i will try them
Sweet, I need some lighting practice! Too bad not all have a .blend. I think this type of practice is awesome and super helpful.
Nice find encn! 
Thanks.
they look realy good the pages on the side…its even better that there and .obj file for them which is workable in many other 3d animation software
ofcourse there being a blend is +
The .blend file of the dinosaur museum is really cool, great use of instanced parts!
The UV maps in the fruit bowl scene was rather hit and miss, I hope it’s a bit better in other scenes.
But the challenge concept is great, it think it’d be a hit if Blendercookie ran something similar.
That’s a really good idea actually, would also be cool if the community got together and tried out these challenges for a couple of weeks at a time 
I think it would be especially valuable as testing-grounds for Cycles. A given high-quality production scene eliminates a lot of random error factors.
I love the way the 9-billion polys-scene ( http://blenderartists.org/forum/showthread.php?249664 ) has become a sort of community project to tweak and improve and compare between machines.
btw… if anyone finishes those lighting challenges, or creates clean basic .blend-scenes… by all means, post:)
Quite a few of those have .blends in the ‘Lighting Challenge’ section on that other 3D forum.
I think it would be especially valuable as testing-grounds for Cycles.
Haha yep, this is how I plan to learn Cycles lighting well.
it think it’d be a hit if Blendercookie ran something similar
That would be so awesome!