  It is pointed out that certain CP-odd momentum correlations in the production
and subsequent decay of tau pairs in $e^+e^-$ collisions get enhanced when the
$e^-$ is longitudinally polarized. Analytic expressions for these correlations
are obtained for the single-pion decay mode of $\tau$ when $\tau^+\tau^-$ have
a ``weak" dipole form factor (WDFF) coupling to $Z$ . For $e^+e^-$ collisions
at the $Z$ peak, a sensitivity of about 1-5$\times 10^{-17}$\mbox{$e$ cm} for
the $\tau$ WDFF can be reached using a {\em single} $\tau^+\tau^-$ decay
channel, with $10^6\, Z$'s likely to be available at the SLC at Stanford with
$e^-$ polarization of 62\%-75\%.
