I need to convert my e-book PDF business documents (Invoices & Purchase Orders) into XML. Is there a web tool that will do that?
Yes. There is a online tool called EDI Link connect. You convert PDF to XML by emailing the document to their server and it emails back a XML. That's the basic version anyway. It designed for business documents so that might do it for you.
Here is a link if you are interested: http://ecdynamics.com/pdf-conversion.php