  As the highest-energy photons, gamma rays have an inherent interest to
astrophysicists and particle physicists studying high-energy, nonthermal
processes. Gamma-ray telescopes complement those at other wavelengths,
especially radio, optical, and X-ray, providing the broad, mutiwavelength
coverage that has become such a powerful aspect of modern astrophysics.
Multiwavelength techniques of various types have been developed to help
identify and explore unidentified gamma-ray sources. This overview summarizes
the ideas behind several of these methods.
