For quite a while now OpenOffice has been promising the ability to import and edit PDF files. Although not released with the program itself, you can grab the Sun PDF Import extension to do just that.
This extension is in beta and is available multi-platform for Windows, Linux and MacOS X systems.
Tests that I ran were pretty good. The text in the PDF file is imported well and in a way I could edit the text, font settings and images. There was a small problem in that the document that was shown to me had colors inverted (black background with white font). But, don’t ask me why, the imported file actually contained 2 layers. Deleting the one on top will show you the layer with correct colors and fully editable.
The extension is in beta but it is sure worth a try and beats editing the PDF through an image software like I used to do.