Neutrinos are powerful probes of both astrophysics and fundamental particle physics at the highest energies. Weakly interacting and uncharged, they propagate undeterred and unabsorbed through the universe. In the last decade, we have observed a flux of high-energy (TeV-scale) neutrinos and through a multi-messenger lens — the combined observations of neutrinos and other messengers like photons — we are starting to see hints of energetic neutrino sources for the first time. At higher energies still, beyond the PeV scale, we can probe the most energetic sources of both neutrinos and cosmic rays, but current neutrino experiments become too small to observe a sizable flux. With long propagation lengths in both ice and air, radio detection offers an attractive solution to building the gigaton-scale detectors needed by allowing us to build sparse detectors sensitive to neutrinos over hundreds of kilometers. In this talk, I will review the landscape of current radio neutrino experiments, how they may lead to discoveries of neutrinos in a new energy band, and what they can reveal about the multi-messenger universe.