  Recently several proposals were put forward to determine the parity of narrow
baryonic resonances, in particular the $\Theta^+$. In these proceedings we will
briefly comment on the general problems in this task and then discuss in detail
the potential of reactions of the type $\vec N\vec N\to\Theta^+Y$, where $Y$
denotes a hyperon (either $\Sigma$ or $\Lambda$) and the arrows indicate that a
polarized initial state is required. Besides reiterating the model--independent
properties of this class of reactions we discuss the physics content of some
model calculations.
