Over the past decade, scientists have learned how to manipulate the interaction of radiation with structured materials to an unprecedented level. For decades, our world was limited to materials with primarily positive permittivities and permeabilities, with a few exceptions such as plasmas, for example, whose permittivities can be negative. The research in metamaterials coupled with the rapid advancements in micro- and nanofabrication technologies has removed this limitation and has opened the door to almost arbitrary material properties with some extraordinary consequences across the electromagnetic spectrum, ranging from radio frequencies to optical frequencies. These developments have been strongly complemented by the developments in periodic dielectric photonic crystals where band-gap effects lead to mind-blowing dispersion characteristics and consequent effects. Almost simultaneously, the optics of metals has been brought to center-stage where the plasmonic excitations enable the electromagnetic radiation to interact resonantly with the structured material at very small sub-wavelength scales. These interactions prove to be the key to manipulating the optical near-field, and surprising effects such as sub-wavelength scale imaging by so-called super-lenses made of negative refractive index or plasmonic materials have been discovered.