Skim PDF Reader
Skim is a viewer for Portable Document Format (PDF) files, intended for easy reading and studying PDF documents.
You can search PDF files, bookmark them, add notes, highlight sections, and take "snapshot" for easy reference. Skim can also open PostScript (PS) files, converting them to PDF.
In addition, with Skim you can fully concentrate on reading the PDF file in a powerfull full screen mode, or give full screen presentations of your PDF file.