This review covers various approaches now available to enhance the surface area of stationary phases fabricated in the porous layer open tubular (PLOT) format for use in liquid-phase-based separation techniques and catalytic applications. We focus attention on the preparation of porous polymers (monoliths), since many procedures have already been described related to the production of PLOT columns with distinctive properties and coatings at the column wall. We discuss advantages and limitations of these methodologies with regard to materials used and the demonstrated application.