OpenOffice 3 = Free PDF Editor + Acrobat Writer
Though you write PDF documents without Adobe Acrobat, there aren’t many choices for editing PDF files. Most PDF editors are either commercial or offer very limited functionality.

All this is expected to change when Sun releases OpenOffice 3 in the next few months as it includes native PDF import and export features. See the slide above.
You will be able import PDF files into Draw (PowerPoint), perform the edits and then export them as hybrid PDFs meaning you can edit the PDF files back again in OpenOffice.
OpenOffice 3 will be available on Windows and Mac. It may not have all the PDF editing features of Acrobat but may still satisfy the needs of most users who only require basic editing.
Planned Features [pdf] - Thanks Mike MacCana

this is probably the best free pdf editor around i noticed. most of the other free ones are free trial which you have to pay later on.
Wow, thanks for posting this! I’ve been hunting for a good free PDF editor for months now, so at least I have something good to look forward to.
“OpenOffice 3 will be available on Windows and Mac” Not on GNU/Linux? You should do your research better. Open Office 3 will be available for GNU/Linux too!
Thanks
OOo Draw is not a PowerPoint equivalent…
It’s great to see PDF Editing will be available in OpenOffice3. For those who can’t wait, there are already two open source PDF Editor’s available. flpsed and PDFEdit, the latter being the more functional of the two. I detailed my experiences with them on my blog.