Thanks! I traced some photos that looked like they had good texture. I think I'll be using that method in the future, not just for backgrounds, but for all sorts of stuff.
Thanks, Similarius. Bwansy, you might be interested in this post by an Illustrator user (applies to Inkscape too though). In fact, the gray texture I applied in the image background is a photograph of some clover, just simplified (Ctrl+L) a bit.