  A rotating thin shell in a (2+1)-dimensional asymptotically AdS spacetime is
studied. The spacetime exterior to the shell is the rotating BTZ spacetime and
the interior is the empty spacetime with a cosmological constant. Through the
Einstein equation in (2+1)-dimensions and the corresponding junction conditions
we calculate the dynamical relevant quantities, namely, the rest
energy-density, the pressure, and the angular momentum flux density. We also
analyze the matter in a frame where its energy-momentum tensor has a perfect
fluid form. In addition, we show that Machian effects, such as the dragging of
inertial frames, also occur in rotating (2+1)-dimensional spacetimes. The weak
and the dominant energy condition for these shells are discussed.
