Recently I've written a little program for the batch change on livejournal posts's visibility settings for Free accounts (I needed to close "private" posts for several years and it's toooooo long to make manually).
I thought that somebody can need this program and decided to share it=) It was tested on my own journal.
Instructions and download link on page http://jehy.ru/soft.en.html .
UPD: program works on Windows, doesn't require any libraries.
UPD 2: Source code (C++) available.
UPD 3: Works perfectly on Linux with Wine.