To scale a texture there is a little box named Scale in the right sidebar texture window. You can use that to increase or decrease the texture scale on any object I believe. I know I've played with it to do just what you are describing, making texture on hills smaller so they look farther away. In the case of my Junk render (posted at Cornucopia but not here yet) I used it to enlarge an environment to make small plants appear to be trees or large plants seen from a distance. The reason for that was poly count, when I tried it with a tree environment my count went into the billions, where with the smaller plants it stayed at a more reasonable level.