Manipulation of structure at the nanoscale and elucidation of structure-properties-application relations are critical in designing materials with targeted characteristics. In this talk, the powerful tool of using restricted environments to direct the growth of a variety of technologically important nanomaterials and control important structural features will be demonstrated. Paradigms will include growth of quantum semiconductor nanostructures in self-assembled block copolymer nanoreactors, directed growth of oriented zeolite materials on appropriately patterned/seeded substrates, and growth of carbon nanotubes and related morphologies inside the pores of inorganic matrices. Aspects of control over dimensions, shape, orientation, and functionalization, and potential for integration of these structures into multi-functional systems will be discussed.