Although there aren't any formal releases of Kninja since 0.1, you can download a fully functional snapshot of the SVN revision 353. It still has the subversion information, so if you would like to keep up to date and you have subversion installed, an update is as easy as "svn update".
SVN revision 353 contains a detailed README.txt, reading this first is highly recommended. If you really don't want to do this, the example configuration file is kninja/files/kninja.conf.example, and should be renamed to kninja/files/kninja.conf.
Kninja version 0.1 released Monday April 1st, 2007! Download!
You still have the option of keeping up with the latest Kninja via subversion:
$ svn co http://kninja.svn.sourceforge.net/svnroot/kninja