Complementing plasmonic slot waveguides with highly nonlinear organic materials has rendered a new generation of ultracompact active nanophotonic components that are redefining the state of the art. In this paper, we review the fundamentals of this so-called plasmonic- organic-hybrid (POH) platform. Starting from simple phase shifters to the most compact IQ modulators, we introduce key devices of high-speed data communications. For instance, all-plasmonic Mach-Zehnder modulators (MZMs) are reviewed and long-term prospects are discussed. This kind of modulator already features unique properties such as a small footprint (2), a large electro-optic bandwidth (> 110 GHz), a small energy consumption (~25 fJ/b), a large extinction ratio (> 25 dB) in combination with a record small voltage-length product of 40 Vμm. Finally, as an example for seamless integration we introduce novel plasmonic IQ modulators. With such modulators we show the generation of advanced modulation formats (QPSK, 16-QAM) on footprints as small as 10 μm × 75 μm. This demonstration ultimately shows how plasmonics can be used to control both phase and amplitude of an optical carrier on the microscale with reasonably low losses.