You apply it as a standard file plugged into a material, say a lambert.
You then tile it using the 2d/3d input node, cant quite rememberthe naomeclature of the boxes to ass it in (might be as simple as repeat U and repeat V).
So for example in a corridoor with a brick texture jsut repeat the U or V to suit the geometry using either the IPR render of just using the textured view.
"No pressure, no diamonds" Thomas Carlyle