Applying solvation dynamics experiments to viscous liquids or glassy materials near their glass transition involves long lived triplet probes, whose time dependent phosphorescence signals depend upon the local dipolar orientational dynamics, mechanical responses, and polarities. The current understanding of experimental results regarding steady state and time dependent optical line shapes and positions is reviewed with emphasis on the relation to the macroscopic dielectric properties. Several applications are discussed in detail, where advantage is taken of the spatially local instead of ensemble averaging character of this technique. These examples include studies of dynamical heterogeneity, rotational solute/solvent coupling, secondary relaxations in the glassy state, as well as confinement and interfacial effects.