From Coherent Graphics:
Proview is a PDF Editor for Mac OS X. Proview features a wide range of tools to edit existing documents, as well as build new documents from scratch. Easily add or remove PDF attachments, and add text and dates to one or more pages. All functions are applied in real time, and Proview ships with comprehensive interactive help. Perfect for the busy desktop publisher, prepress operator and casual user alike, Proview allows anyone to merge and split files, rotate flip and scale individual pages, or all pages, crop pages and modify the document information. Users can edit encrypted files, as well as decrypt and encrypt PDF documents.