  Within the framework of a simple model, we study single-spin asymmetries for
pion production in hadron-hadron collisions at high-energies with one hadron
polarised. The asymmetries are generated via a mechanism of final (initial)
state interactions. For peripheral kinematics, when the pion belongs to the
fragmentation region of the polarised proton, we find non-zero asymmetries in
the high-energy limit. Numerical results and comparision with existing
experimental data are presented. We also discuss the relationship with odderon
exchange phenomenology.
