From LCDM models of structure formation, massive black hole mergers must be extremely common in the history of the universe. Many should be merging in the local (z~0) universe. I discuss several methods of searching for massive black hole mergers at a range of separations in galactic nuclei and their prospects for success with near-future space telescopes. I discuss the possibility of intermediate mass black hole formation in accretion disks around supermassive black holes and I outline the prospects for a search for radial velocity shifts in the broad FeKa line as a means of searching for relatively wide massive black hole binaries.