  We show that a normal (single particle) current density $J_x$ {\em
transverse} to the ordering wavevector $2k_F{\bf\hat{z}}$ of a charge density
wave (CDW) has dramatic effects both above and {\em below} the CDW depinning
transition. It exponentially (in $J_x$) enhances CDW correlations, and
exponentially suppresses the longitudinal depinning field. The intermediate
longitudinal I-V relation also changes, acquiring a {\em linear} regime. We
propose a novel ``current effect transistor'' whose CDW channel is turned on by
a transverse current. Our results also have important implications for the
recently proposed ``striped phase'' of the high-T$_c$ superconductors.
