  The fabrication of artificial pinning structures allows a new generation of
experiments which can probe the properties of vortex arrays by forcing them to
flow in confined geometries. We discuss the theoretical analysis of such
experiments in both flux liquids and flux solids, focusing on the Corbino disk
geometry. In the liquid, these experiments can probe the critical behavior near
a continuous liquid-glass transition. In the solid, they probe directly the
onset of plasticity.
