OpenOffice.org have just released the first public beta of OpenOffice 3, a Microsoft Office like suite of programs that works across all platforms.
While the current beta of OpenOffice 3 doesn’t support PDF editing yet, it does include lot of new feature including the ability to read and edit Microsoft Office 2007 files formats.
With OpenOffice, you can import PDF files into Draw (PowerPoint), edit the contents of the PDF file and then export the changed file as a hybrid PDF meaning you can later re-edit the generated PDF files back in OpenOffice.