PNG Steganography Source Code
Because people asked to see the revisions of the source code before I even published the article, I threw together a subversion repository of my pngsteg program. There isn't much to see. It can be found here: http://waronpants.net/pngsteg/ . You can get a copy through subversion with
svn co http://waronpants.net/pngsteg/ to navigate the changes with RabbitVCS or TortoiseSVN.