just a note:
if you want a plain ol background rendered with your scene, and don't want it to take shadows, just hook the texture into ambient color instead of diffuse color.

there are also lots of terrain props in freestuff, and i believe stonemason (master of displacement) even has a freebie graveyard...

oops, my mistake, it's just a single grave:
http://home.xtra.co.nz/hosts/polycount3d/Freestuff.htm