There have been spectacular advances in our scientific understanding of the forces that control self-assembly since the phenomenon was first recognized, and given that name about half a century ago. Today it is widely appreciated that the forces that drive the self-assembly of molecules and colloids, materials and polymers into an organized structure or pattern must be expanded beyond those responsible for conventional ionic, covalent, metallic, hydrogen and coordination bonds to include weaker interactions, like van der Waals and Casimir, π-π and hydrophobic, colloidal and capillary, convective and shear, magnetic, electrical and optical forces. Armed with self-assembly as a synthetic tool, powerful chemistry protocols can be developed that are capable of organizing organic and inorganic building-blocks into unprecedented structures and patterns, over several length scales to create novel kinds of integrated chemical, physical and biological systems, which pose myriad of opportunities in nanotechnology. In this article we will briefly examine the physicochemical underpinnings of self-assembly and describe how self-assembly has enabled the practical realization of some nanofabrication objectives by reference to recent examples from our research: a nanoparticle photonic crystal dye laser, three-dimensional nanocrystal and nanowire architectures, an antibacterial silver Bragg mirror and a dye-anchored mesoporous metal oxide electrochemiluminescent device.