The Adobe free service continues to work, as far as I know, but there was a typo in another posting here. This works only for text-searchable PDFs, not for the ones that are graphical. What you get back is also searchable, selectable text, which is great. If you send a graphical PDF (the kind in which you can't select and copy text), Adobe will send you back a file but it will be empty.

pdf2txt@adobe.com

pdf2html@adobe.com