This contribution summarizes investigations of organic-inorganic hybrid materials wherein the inorganic phase is ordered mesoporous silica such as MCM-41 and SBA-15. The review, which covers work performed in the last three years, emphasizes studies of: (1) covalently attached functional groups, (2) new approaches to functionalization, (3) approaches for achieving high densities of uniform functional groups, (4) periodic mesoporous organosilicas (PMOs) with hierarchical ordering, (5) new functional chemistries, and (6) the application of new materials to enantioselective catalysis and emerging areas. The review concludes with the authors outlining some outstanding problems in the field.