Ultra High Energy Cosmic Radiation: Experimental and Theoretical Status

7 pages, 2 figures, to appear in the proceedings of "The Dark Side of the Universe", Madrid, June 2006We give a brief overview of the current experimental and theoretical status of cosmic rays above ~10**17 eV. We focus on the role of large scale magnetic fields and on multi-messenger aspects linking charged cosmic ray with secondary gamma-ray and neutrino fluxes