Guillemets in LaTeX («»)

There are several ways to do this:

With standard methods, you will find \guillemotleft and \guillemotright. For this you need \usepackage[T1]{fontenc} (which is recommended anyways).
Using the language switching capabilities of babel, e.g. \foreignlanguage.
Using csquotes and its \foreignquote command.

Personally, I would recommend the third option.

The similar looking mathmode symbols ≪ and ≫ (much less/greater than) are created with \ll and \gg.

There's also a convenient way to do it with Latin Modern:

\documentclass{article}

\usepackage{lmodern}

\begin{document}

<<Quoted text>>.

\end{document}

You could type it directly if you use an utf8 encoding :

\documentclass{minimal}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\begin{document}
«for exemple»
\end{document}

But, the spacing isn't — at least for french typography — correct

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