The origin of highest energy cosmic rays and cosmic magnetic fields

We summarise the status of the search for the origin of the highest energy cosmic rays. We briefly mention several competing proposals, such as supersymmetric particles, Gamma Ray Bursts also giving rise to energetic protons, interacting high energy neutrinos and cosmological defects, and then concentrate on the possibilities of the propagation of these particles, assuming that they are charged. The distribution of arrival directions of the highest energy particles on the sky ought to reflect the source distribution as well as the propagation history. The present status can be summarized as inconclusive. If we were able to confirm any particular theory these particles beyond 10(20) eV may be turned into tools of high energy physics.