The International Academy of Aeronautics is hosting an art competition to coincide with their Humans in Space Symposium.  It's open to students aged 10 - 17, and submissions can be in the format of 2-D or 3-D visual art, musical compositions, poetry/prose, or digital video.  The deadline for entries is October 13th.  For more information visit their website: http://www.dsls.usra.edu/meetings/IAA/artContest/