  We consider a rescattering mechanism to calculate a leading twist $T$-odd
pion fragmentation function, a candidate for filtering the transversity
properties of the nucleon. We evaluate the single spin azimuthal asymmetry for
a transversely polarized target in semi-inclusive deep inelastic scattering
(for HERMES kinematics) and the double $T$-odd $\cos2\phi$ asymmetry in this
framework.
