  We study signatures of a structured universe in the multi-pole moments,
auto-correlation function, and cluster statistics of ultra-high energy cosmic
rays above 10^19 eV. We compare scenarios where the sources are distributed
homogeneously or according to the baryon density distribution obtained from a
cosmological large scale structure simulation. The influence of extragalactic
magnetic fields is studied by comparing the case of negligible fields with
fields expected to be produced along large scale shocks with a maximal strength
consistent with observations. We confirm that strongly magnetized observers
would predict considerable anisotropy on large scales, which is already in
conflict with current data. In the best fit scenario only the sources are
strongly magnetized, although deflection can still be considerable, of order 20
degrees up to 10^20 eV, and a pronounced GZK cutoff is predicted. We then
discuss signatures for future large scale full-sky detectors such as the Pierre
Auger and EUSO projects. Auto-correlations are sensitive to the source density
only if magnetic fields do not significantly affect propagation. In contrast,
for a weakly magnetized observer, degree scale auto-correlations below a
certain level indicate magnetized discrete sources. It may be difficult even
for next generation experiments to distinguish between structured and
unstructured source distributions.
