A system of charged hard spheres in front of a homogeneous neutralizing bac
kground is studied at low densities using mode-coupling theory. A "Wigner g
lass" phase, the amorphous analog of the Wigner crystal recently found in e
xperiments, is predicted. The melting curve of the Wigner glass obeys n pro
portional to T-3, and the particle localization length is much larger than
the Lindemann criterion would predict. An analysis of transport properties
shows that huge effective particle diameters are responsible for the glassi
fication at low densities. The Stokes-Einstein relation, which is obeyed by
the high-density fluid, implies large Stokes radii at low densities.