I have the same problem... browsing the net I found the following solutions: FLPSED: free, linux, fast, but only adds text http://www.ecademix.com/JohannesHofmann/flpsed.html PDFEDIT: free, linux, rather slow, adds text, lines, highlight, etc... It lacks "undo" funcionallity and most comments will not show up while reading the saved document with xpdf (they show up with acrobat thou). http://sourceforge.net/projects/pdfedit PDFSTUDIO paid but has demo version, java based, linux/windows, rather s...