Some old PDF documents, such as papers from the early '80s, have their pages
in reverse order.  The tools I know about (Acrobat Reader, Mac Preview, etc.)
do not allow one to reverse the page order.  This is a simple script to reverse
the pages of a pdf document.

Installation
============

# Download and install pdftk

  http://www.pdflabs.com/tools/pdftk-the-pdf-toolkit/

# Download reverse-pdf-pages and add it to your path.

# cd to the directory with the pdf you want to reverse

# run reverse-pdf.sh FILE.pdf

This will create the file FILE-rev.pdf which has the pages reversed.