We revisit classical "on shell" duality, i.e., pseudoduality, in two
dimensional conformally invariant classical sigma models and find some new
interesting results. We show that any two sigma models that are "on shell"
duals have opposite 1-loop renormalization group beta functions because of the
integrability conditions for the pseudoduality transformation. A new result
states for any two compact Lie groups of the same dimension there is a natural
pseudoduality transformation that maps classical solutions of the WZW model on
the first group into solutions of the WZW model on the second group. This
transformation preserves the stress-energy tensor. The two groups can be
non-isomorphic such as B_n and C_n in the Cartan notation. This transformation
can be used for a new construction of non-local conserved currents. The new
non-local currents on G depend on the choice of dual group G-tilde.Comment: 28 pages, LaTeX fil