There are some useful and free tools on the Web for creating, modifying and exchanging documents, and here are a few.
I have two sites For PDFs (Portable Document Format). The first site is KoolWire.com, which automatically converts Word (.doc), Powerpoint (.ppt), Excel (.xls), Jpeg, GIF, Rich Text Format (.rtf),and Text (.txt) files to PDFs. You attach your files, email them to the site, and they are immediately returned to your email as PDFs. Couldn't be easier.