To compress multiple pdfs we 
<ol>
<li><a href="/compress_pdf_files">convert them to postscript files</a> <small>(step 1)</small></li>
<li>use the batch files describe below to convert them to compressed pdfs</li>
</ol>
<br>
Some problems we experienced:
<ul>
<li>We have some pdfs made from large scanned pages (1bit, high resolution images, usually bigger than the pdf page size). These take forever to convert and the images in the pdf come out distorted</li>
<li>If you copy/paste the text from the compressed pdfs it is messed up</li>
</ul>