Hiding the title of the bibliography

The thebibliography environment uses \section*{\refname} (article class and similar classes) or \chapter*{\bibname} (book and report and similar classes) internally. Redefining that macro locally to take and discard two arguments (one for *, one for the actual argument) will remove the headline.

Example:

\documentclass{article}

\begin{document}

\begingroup
\renewcommand{\section}[2]{}%
%\renewcommand{\chapter}[2]{}% for other classes
\begin{thebibliography}{}
\bibitem{ano05}
    A. Nonymous et al.\ 2005
\bibitem{oe04}
    A.N. Other \& S.O.M. Ebody 2004
\end{thebibliography}
\endgroup

\end{document}

This also works for BibTeX's \bibliography{..} because it uses thebibliography internally. For this use:

\begingroup
\renewcommand{\section}[2]{}%
%\renewcommand{\chapter}[2]{}% for other classes
\bibliography{mybibfile}
\endgroup

If you use biblatex you can use the bibliography heading none which was added in version 1.5 (see the manual, section 3.5.7). I've got an earlier version so I can't try it but I think the following is an example of this option in use:

\documentclass{article}

\usepackage{biblatex}

\usepackage{filecontents}

\begin{filecontents*}{database.bib}
@book{texbook,
    author  = {Donald E. Knuth},
    title   = {The {{\TeX}book}},
    publisher   = {Addison-Wesley},
    date    = {1984}
    }
\end{filecontents*}

\bibliography{database.bib}

\begin{document}

\cite{texbook}

\printbibliography[heading=none]

\end{document}

Redefine the \binsection-command. You want to have it empty, so do:

\renewcommand{\bibsection}{}

(Credits to http://latex.org/forum/viewtopic.php?t=4089, where I found the solution which worked for me.)