If you go to this link and search for "background" you should be able to find something.  You might have to resize as needed.

http://mystic-nights.com/directory/index.php

Also, try asking in the Terragen, Vue and the Bryce forum. Those 3 programs make really nice backgrounds.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi