OpenOffice.org extension will add PDF editing
Easy PDF editing is coming to OpenOffice.org, but you'll have to be patient for a few months. Recently posted to the OpenOffice.org Extensions site, the Sun PDF Import extension (SPI) is only in beta, and only works with recent developer builds of OpenOffice.org 3.0, which is scheduled for September release. Right now, the quality of the final release is anybody's guess, but the beta's capabilities fall squarely in the middle of the available PDF import tools.
To investigate SPI, you need to download and install a snapshot build of OpenOffice.org 3.0. Then, from within the build, you can install SPI from Tools -> Extension Manager. The next time you start OpenOffice.org 3.0, you'll be able to open PDF files from any of the options for opening an existing document in the File menu.
By default, SPI opens PDF files in the Draw application, although you could also use Impress, which shares much of the same code. This default might seem strange at first, especially if your PDF file is text. Actually, though, using Draw is logical, given the limitations of the PDF format. No application -- not even Acrobat, the proprietary PDF editor made by Adobe, the company that wrote the PDF specifications -- is able to edit more than a single line while preserving format.