typing \end{verbatim}
You can create a new environment that ensembles the verbatim environment, like:
\documentclass{article}
\usepackage{verbatim}
\newenvironment{realverbatim}{\verbatim}{\endverbatim}
\begin{document}
Test of the new \verb~verbatim~ environment:
\begin{realverbatim}
\begin{verbatim}
foo
\end{verbatim}
\end{realverbatim}
\end{document}
Try
\usepackage{verbatim}
\verb+\begin{verbatim} foo \end{verbatim}+
or, if you want it on separate lines
\verb+\begin{verbatim}+\\
\verb+foo+\\
\verb+\end{verbatim}+
or, if foo is long,
\verb+\begin{verbatim}+
\begin{verbatim}
foo
\end{verbatim}
\verb+\end{verbatim}+
I don't think that there is any really sensible trick which will work with verbatim
directly. I would use another verbatim-like environment from the listings
or the fancyvrb
package.