During a bit of web surfing done while writing my previous post, I noticed that the National Space Society is holding the Space Settlement 2009 Calendar Art Contest. That link is just the flyer; here are the rules and prizes. Hopefully this becomes a long-term annual contest.
The rules sound similar to what I remember from last year's contest. There will be 12 winners whose artwork will appear in the 2009 calendar. The contest is divided by subject matter: orbital, asteroid, Moon, and Mars settlements. In addition to the main prize, which is having their artwork appear in the calendar and on the NSS website, the winners get cash, copies of the calendar, and other space and art prizes like software, paid memberships, and signed books.
The contest deadline is December 31, 2007!