End notes and Foot notes in LaTeX

So I was writing up notes for a reading group on Afghanistan, and it has apparently become fashionable to use endnotes in the humanities. Being fond of Edward Gibbon, I use footnotes excessively. Irritating everyone, I use both while making it indistinguishable whether I refer to a footnote or endnote by a superscripted number.

How to do this in LaTeX? Quite simple:

\documentclass{article}

\usepackage{endnotes}

\makeatletter
\newcommand*{\dupcntr}[2]{%
    \expandafter\let\csname c@#1\expandafter\endcsname\csname c@#2\endcsname
}
\dupcntr{endnote}{footnote}
\renewcommand\theendnote{\thefootnote}
\makeatother

\begin{document}
Blah blah blah.
\end{document}

It turns out to work quite well.

I modified some macros from a TeX Stackexchange discussion on "slave counters"...so I get only partial credit.