First option using memoir class
The memoir class provides the \plainbreak and \fancybreak commands for this purpose (see the manual, texdoc memoir, pp. 99-101). There is also a \plainfancybreak command that will omit the fancy symbols if the break occurs at the top of a page.
\documentclass{memoir}
\usepackage{lipsum}
\newcommand{\starbreak}{%
\fancybreak{* * *}%
}
\begin{document}
\lipsum[1]
\plainbreak{2}
\lipsum[2]
\starbreak
\lipsum[3]
\end{document}
Second option for any class
To add to @Boris's answer, you can use the psvectorian package to access many beautiful ornaments that are well suited to this purpose.
Here I define two commands: the first just puts ornaments as a break in the text; the second puts a header text plus ornaments.
The psvectorian package allows you to include beautiful PostScript illustrations, which are listed by number in the documentation (texdoc psvectorian, in French but the examples are in LaTeX). The basic command is \psvectorian[width=1em]{2} where the {2} specifies that you want image 2 as listed in the documentation.
You can either include them directly as in this example (which, because it uses PostScript, must be compiled with latex -> dvips -> ps2pdf, not with pdflatex). Or you can compile the graphics separately (e.g., using the standalone package) and just use \includegraphics from the graphicx package to include them.
\documentclass{article}
\usepackage{lipsum}
\usepackage{psvectorian}
\newcommand{\ornamentleft}{%
\psvectorian[width=2em]{2}%
}
\newcommand{\ornamentright}{%
\psvectorian[width=2em,mirror]{2}%
}
\newcommand{\ornamentbreak}{%
\begin{center}
\ornamentleft\quad\ornamentright
\end{center}%
}
\newcommand{\ornamentheader}[1]{%
\begin{center}
\ornamentleft
\quad{\large\emph{#1}}\quad % style as desired
\ornamentright
\end{center}%
}
\begin{document}
\section{First section}
\lipsum[1]
\ornamentbreak
\lipsum[2]
\ornamentheader{Header but not a section command}
\lipsum[3]
\end{document}
