The purpose of this review paper is to bring a brief summary of the research literature in a wide variety of fields, each sharing one specific characteristic: the subjects of examination in each field are porous at some level. These fields range from the development of transplant materials for bone to the tertiary extraction of petroleum from reservoir rocks. The scale of the porosity ranges from the ultra-fine pores in coal, on the order of 20 to 50 Angstroms, to the much coarser micropores in sandstone rocks, on the order of fractions of a millimeter.