Cosmic neutrinos probe fundamental physics at scales far beyond the reach of terrestrial accelerators or other cosmic messenger particles. The low expected flux of cosmic neutrinos drives the need for neutrino experiments to achieve larger exposures and lower thresholds. Radio experiments can achieve such large exposures by taking advantage of the coherent broadband radio emission resulting from ultra-high-energy (E>10^17 eV) neutrino interactions. In this talk, I will review results from current radio experiments, like ANITA, and discuss future concepts, like BEACON and RNO/ARA, aimed at understanding cosmic engines and exploring particle interactions at the highest energies.