Ive seen this great challenge from CGtalk today, its open to everyone and the model is included (wich can be used to test Octane render also)
Challenge duration is
15 December 2009 – 15 March 2010
More informations and instructions on Ronen Bekerman website
I know Octane render is only in demo but it would be cool to see some submissions done with Octane render
Some work in progress by people around the world can be found here