The terahertz (THz) regime, generally considered to be 0.3-10 THz, is rich with emerging possibilities in sensing, imaging and wireless communications. Since it is non-ionizing and can exploit endogenous contrast mechanisms, it has particular potential for biological applications. These range from screening persons for concealed weapons to advanced biomedical diagnostics at the sub-cellular level. Supporting these applications are electronic techniques for generating, detecting and managing THz "light," including broadband antennas and scanning probes.