Challenges Found

http://www.adesignaward.com/competitions/computergraphics.html - Big Award

https://market.renderosity.com/signup.php -smaller compotitions

http://3d.about.com/od/Career-Resources/tp/More-Places-To-Show-Your-3d-Art.htm -about

http://www.asingularcreation.com/calls-to-artists.php#/?i=1 -free monthly comp

http://area.autodesk.com/blogs/craig/mudbox_challenge_armed_and_dangerous -mudbox challenge