  Measurements in the radio regime embrace a number of effective approaches for
WISP searches, often covering unique or highly complementary ranges of the
parameter space compared to those explored in other research domains. These
measurements can be used to search for electromagnetic tracers of the hidden
photon and axion oscillations, extending down to ~10^-19 eV the range of the
hidden photon mass probed, and closing the last gaps in the strongly favoured
1-5 micro-eV range for axion dark matter. This provides a strong impetus for
several new initiatives in the field, including the WISP Dark Matter eXperiment
(WISPDMX) and novel conceptual approaches for broad-band WISP searches in the
0.1-1000 micro-eV range.
