Solid state physics is a complex area which needs a full arsenal of experimental techniques to uncover all its intriguing aspects. This book presents results from methods where phenomena in solids are observed from viewpoints that fall outside the experimental mainstream, but have brought unique information to the understanding of magnetism, superconductivity, interface physics and the physics and chemistry of metal/hydrogen systems, in particular diffusion phenomena. The text is not method-oriented, but rather centers on relevant physical problems; it puts the specific and often unique information gained into a general perspective, giving a broad overview to students and solid state or theoretical physicists.