You can also use a Texturemapping Tool to assign Textures to diffrent parts of a Mesh. Lithunwrap 1.3 is freeware. Usualy you should use only a minimum of texture-files (which are then seperate surfaces). But using Lithunwrap you can also put several Texture-Materials on one Texture image and then move the vertices, triangles or groups of the Mesh to the wanted positions.