White light luminescence and room-temperature lasing throughout the visible are demonstrated for ZnO nanocolumns grown on Au-coated tin-oxide glass. The directionality of the emission, the lasing threshold, and the observed mode spacing are all consistent with Fabry-Perot lasing cavities. The Figure shows a cross-sectional SEM image of ZnO nanocolumns with an average nanocolumn length of similar to3 mum.