  Exclusive photoproduction of heavy quarkonia in high-energy ultraperipheral
ion-ion interactions (gamma A --> V A, where V = J/Psi,Upsilon and the nucleus
A remains intact) offers a useful means to constrain the small-x nuclear gluon
density. We discuss preliminary results on J/Psi photoproduction in Au-Au
collisions at RHIC energies, as well as full simulation-reconstruction studies
of photo-produced Upsilon's in Pb-Pb interactions at the LHC.
