Observing optical polarimetric variability from BLAZARS to CVs

One of the South African Astronomical Observatory's (SAAO) niche areas is in observational optical polarimetry. A particularly specialised instrument is the HIPPO (HIgh-speed Photo-POlarimeter), which was designed and built to observe variable and polarised astronomical sources. I will describe HIPPO's capabilities and present two new results: The discovery of polarised QPOs from a BLAZAR and the discovery of highly modulated polarisation from the first white dwarf "pulsar".