  We obtain the relaxation time for the shear viscous stress for various
geometries using the "membrane paradigm" formula proposed recently. We consider
the generic Schwarzschild-AdS black holes (SAdS), the generic Dp-brane, the
Klebanov-Tseytlin (KT) geometry, and the N=2* theory. The formula is the "shear
mode" result and is not fully trustable, but it may be helpful to learn some
generic behaviors about the relaxation time. For example, a simple formula
summarizes all known results for SAdS, and a single expression summarizes the
results for the Dp-brane and the KT geometry.
