At zero temperature the Coulomb Branch of N = 4 super Yang-Mills theory is
described in supergravity by multi-center solutions with D3-brane charge. A
t finite temperature and chemical potential the vacuum degeneracy is lifted
, and minima of the free energy are shown to have a supergravity descriptio
n as rotating black D3-branes. In the extreme limit these solutions single
out preferred points on the moduli space that can be interpreted as simple
distributions of branes - for instance, a uniformly charged planar disc. We
exploit this geometrical representation to study the thermodynamics of rot
ating black D3-branes. The low energy excitations of the system appear to b
e governed by an effective string theory which is related to the singularit
y in spacetime.