Plasmon waveguides, which are based on resonance between collective motions in noble-metal nanoparticles and visible light, should be useful in building novel nanoscale optical devices; calculations predict that corner. switch, and splitter elements are feasible. Experiments with microwaves on macroscopic analogues confirm the guiding and splitting effects. The Figure shows a corner element made of 50 nm circle divide, 75 nm spaced gold dots.