The Gnomon Workshop throws these really cool contests every month. They have two categories 2D image and 3D image and every month they give away 4 prizes per category. The prizes are amazing, first place gets 25 gnomon dvd's, second place gets 15 dvd's and so on... I personally really enjoy the gnomon dvd's and learn so much from their amazing instructors. I was lucky enough to have one of my entries for the 2D image June contest chosen for second place. I won 15 dvd's and am very excited to receive my winnings in the mail. Also the work that is submitted to these contests are pretty amazing and always fun to see what other people come up with for the monthly theme.
If you haven't already been to the Gnomon forums you should check them out and create a profile. There is a lot of good stuff going on over there and who knows maybe you will be inspired by some of the artwork happening over there. http://forums.thegnomonworkshop.com/showthread.php?t=5660