\documentclass{article}

\documentclass{article}
\usepackage{pslatex}
\begin{document}
Here is a footnote.\footnote{Stuff.}

This is text followed by a footnote.\footnote{In this note I make some
point which I will want to refer to from another location, so I label
it.\label{bar}}

Here is some intervening and unrelated footnote.\footnote{{\fontencoding{OT1}\fontfamily{cmr}\fontshape{it}\selectfont{}The quick brown fox
jumps over the lazy dog}}

Here is the place where I want to refer to the same footnote as
before, which I labelled `bar'.\footnotemark[\ref{bar}]
\end{document}