Including overly large graphics

Sometimes a graphic (or table or what have you) is simply too large to fit on the page without extending into the margins. Here's a simple way to center the graphic in the page without getting any Overfull hbox warnings.

\par
\hbox to\textwidth{\hss\includegraphics{foo}\hss}%
\par

The two \par aren't really essential. They're just to ensure the graphic is in a paragraph by itself. Replace \includegraphics with any other centered material. Note that this actually causes the graphic to extend an equal amount into the margins. If the margins aren't the same size, this is not centering on the page, but it's probably what you want anyway.