  We obtained the energy transport velocity distribution for a three
dimensional ideal cloak explicitly. Near the operation frequency, the energy
transport velocity has rather peculiar distribution. The velocity along a line
joining the origin of the cloak is a constant, while the velocity approaches
zero at the inner boundary of the cloak. A ray pointing right into the origin
of the cloak will experience abrupt changes of velocities when it impinges on
the inner surface of the cloak. This peculiar distribution causes infinite time
delays for the ideal cloak within a geometric optics description.
