  In this paper I present an action principle for odd dimensional AdS gravity
which consists of introducing another manifold with the same boundary and a
very specific boundary term. This new action allows and alternative approach to
the regularization of the theory, yielding a finite euclidean action and finite
conserved charges. The choice of the boundary term is justified on the grounds
that an enhanced 'almost off-shell' local AdS/Conformal symmetry arises for
that very special choice. One may say that the boundary term is dictated by a
guiding symmetry principle. Two sets of boundary conditions are considered,
which yield regularization procedures analogous to (but different from) the
standard 'background substraction' and 'counterterms' regularization methods.
The Noether charges are constructed in general. As an application it is shown
that for Schwarszchild-AdS black holes the charge associated to the time-like
Killing vector is finite and is indeed the mass. The Euclidean action for
Schwarzschild-AdS black holes is computed, and it turns out to be finite, and
to yield the right thermodynamics. The previous paragraph may be interpreted in
the sense that the boundary term dictated by the symmetry principle is the one
that correctly regularizes the action.
