Theoretical models related to dark matter, motivated in part by current data from PAMELA, Fermi, DAMA, and others, have proposed that there are long-range forces mediated by new gauge bosons with masses in the MeV to GeV range and very weak coupling to ordinary matter. The experimental constraints on the existence of these new gauge bosons are quite weak. This talk will review the motivation for dark forces and present a broad array of probes of this physics. These probes include high-luminosity e+e- colliders, such as BaBar and BELLE, whose existing data sets may contain thousands of spectacular events; new high-intensity fixed-target experiments at electron accelerators, such as Jefferson Laboratory and SLAC; and indirect astrophysical probes, such as gamma-ray observations of Milky-Way dwarf satellite galaxies, which constitute some of the least luminous and most dark matter dominated galaxies known.