A recently discovered and as yet incompletely understood effect promises to become an excellent tool for investigating molecules adsorbed onto metal surfaces. The effect consists of a spectacular enhancement—by factors of up to around106—of Raman scattering by monolayers of molecules adsorbed onto microscopically rough metal surfaces (rough on a scale of 500–1000 Å). One of the most exciting prospects is that the effect will become a useful analytical tool for studying catalysis and other processes that take place on surfaces. As Elias Burstein, one of the early investigators in the field, put it, we are just learning how to put microscopic amplifiers onto metal surfaces.