A Pie Chart (pgf-pie.sty)
\documentclass{article}
\usepackage{pgf-pie}
\begin{document}
\begin{tikzpicture}
\pie
[explode={0,0.5,0,0.75,0},% offset segments 2 and 4
color={yellow,cyan,green,pink,orange},% segment colour
text=legend% create a legend
]% settings
{5/A,10/B,15/C,30/D,40/E}% values and labels
\end{tikzpicture}
\end{document}
Download pgf-pie-sample.tex or pgf-pie-sample.pdf.