  Weak values are usually associated with weak measurements of an observable on
a pre- and post-selected ensemble. We show that more generally, weak values are
proportional to the correlation between two pointers in a successive
measurement. We show that this generalized concept of weak measurements
displays a symmetry under reversal of measurement order. We show that the
conditions for order symmetry are the same as in classical mechanics. We also
find that the imaginary part of the weak value has a counterpart in classical
mechanics. This scheme suggests new experimental possibilities.
