thank you JamesNC for answering why it's so hard to do and why most would be better served converting to HTML from the source with the same proggy that creates the PDF.

anyways, on a larkish whim i tried this last night:

$ mkdir ~/public_html/pdf_test
$ cd ~/public_html/pdf_test
$ convert ~/PDF/ch10.pdf ch10_%02d.html
[download]

and imagine my surprise when it actually worked! but in truth, it doesn't work that well, it does the obvious of PDF -> image -> gif, and the html files are just wrappers to load the gif images of the pages. but, if it's thumbnails of PDF you want then with a bit of scaling this will work. but it's more of a pain to read a giant gif than to download the PDF and use Acrobat.

if you really want HTML/GIF versions of a PDF then take a look at ImageMagick which provides lot's of conversion options.