\AtBeginSection[special_star_text]{text}

- the given text will be inserted at the beginning of every section
- analogical commands exist for subsection and document



\AtBeginSection[]
{
\begin{frame}<beamer>
\frametitle{Outline}
\tableofcontents[currentsection]
\end{frame}
}

- inserts the outline of the presentation at the beginning of every section
  with the coming section highlighted
- place before the first \section{} command