It is a free conversion utility that takes AutoCAD DWG files and converts them to PDF files. There is a new version of OttoPDF that supports compression of the PDF files, this feature is currently only accessible through the batch mode of OttoPDF.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.