Passing data among handlers

[Paul J. Lucas]

        Perhaps I've missed it, but is there a better way than the
        "notes" mechanism to pass data among handlers?

        The "notes" mechanism not only requires the notes to be
        scalars, but, apparantly, said scalars must also be simple
        strings, i.e., no binary data crammed into a scalar.

        Better ideas?  Odds of enhancing the "notes" mechanism?

        - Paul