It's possible to have pdfpages number the pages of the document it including using the following command:
\includepdfset{pagecommand=\thispagestyle{plain}}
(cf. Base document page numbers with pdfpages )
Unfortunately, this doesn't play nicely with nup (which puts multiple source pages on one target page); the numbering is applied to the output pages rather than the input pages:
\documentclass{article}
\usepackage{pdfpages}
\includepdfset{pagecommand=\thispagestyle{plain}}
\begin{document}
\includepdf[nup=2x3,pages={1-6},frame=true]{<use any PDF file>}
\end{document}
Cf. the '1' at the bottom of this, where I would want 1-6 on the pages:

Is there any way around this?
\thepageis printed in order to achieve the desired output. It will also have to be done somewhat manually, since the page numbers of the input document could be anything. That's just my opinion. – Werner Dec 07 '12 at 20:54