Following a brief review of charged hard sphere structural models and the statistical mechanical theory of the freezing of ionic melts into a superionic phase, recent experimental findings on copper halides, specifically CuBr have been considered. These findings are primarily based on neutron diffraction and X-ray absorption spectroscopy. AgI has been briefly discussed, and certain controversial key issues have been identified. Liquid metallic plasmas have been examined under a wide range of thermodynamic conditions. After reference to the heavy alkalis, Cs and Rb, recent shock wave experiments on liquid H and D and computer simulations on isochoric heating of dense fluid H have been discussed. The likely relevance of liquid metallic hydrogen to the structure of giant planets and brown dwarfs has also been considered. Finally, AB mixtures have been examined when A and B are metal atoms, e.g. A = heavy alkali, B = noble metal or Sb; and then when A is a metal atom and B a molten salt. In both cases, attention has been paid to the possibility of metal-nonmetal transitions as the concentration of A relative to B is varied.