To get automatic line breaking with listings
you need to specify breaklines=true
:

\documentclass{article}
\usepackage{listings}
\lstset{basicstyle=\small\sffamily,
numbers=none,
frame=tb,
columns=fullflexible,
showstringspaces=false,
breaklines=true
}
\begin{document}
\begin{lstlisting}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam consectetur nulla a ante ullamcorper sed mattis massa fringilla. Mauris et leo nisl. Sed tortor lorem, vestibulum ut fermentum a, sollicitudin in arcu. Vivamus leo purus, imperdiet quis scelerisque et, varius non enim. Nunc scelerisque velit et dui porttitor at vulputate lorem convallis. Nam vitae erat ac urna semper adipiscing. Proin quis justo nibh. Proin ultricies ultricies libero. Nunc sodales sapien vel purus ultricies sodales. Curabitur non semper magna. Nullam varius dapibus leo, ac imperdiet nulla tempus vitae. In et turpis ut turpis facilisis tristique. Phasellus interdum, justo a semper aliquam, ante diam consequat justo, a egestas nisi lorem sit amet erat. Nam justo nunc, vulputate ac luctus et, ullamcorper eu mi. Pellentesque ut dui nulla, ut sagittis dui. Donec eget ligula non dui tristique auctor at vel sapien.
\end{lstlisting}
\end{document}
\documentclass
and the appropriate packages so that those trying to help don't have to recreate it. If you can't get it to compile at least post what you have attempted so far. – Peter Grill Nov 12 '11 at 2:12