  Exclusive vector meson photoproduction, $pp\to ppV$ and $\bar pp\to\bar ppV$
occurs with significant rates at hadron colliders. The reaction can be used to
study the gluon distribution of protons. Vector mesons may be produced with
either proton as a target; because of interference between the two production
channels, the $p_T$ spectra of vector mesons produced in $pp$ and $\bar pp$
collisions are quite different. Because of the unique event signature, vector
meson photoproduction can be separated from hadroproduction events, despite the
small ratio of cross sections. We consider production of $J/\psi$ and
$\Upsilon$ at RHIC, the Tevatron and the LHC.
