  The shear viscosity to entropy ratio ($\eta/s$) is estimated for the hot and
dense QCD matter created in Au+Au collisions at RHIC ($\sqrt{s_{NN}}=200$ GeV).
A very low value is found $\eta/s \sim 0.1$, which is close to the conjectured
lower bound ($1/4\pi$). It is argued that such a low value is indicative of
thermodynamic trajectories for the decaying matter which lie close to the QCD
critical end point.
