As promised, I wrote an article about setting up Samba in KDE. It is not immediately obvious how to set it up in KDE, but it is easy if you follow the steps I have illustrated. I have tested this method, so it should work for most Linux distributions and other Unix variants, as long as they have standard KDE installations.
Boxee recognizes Samba shares immediately. All you have to do is add the ones you want in the sources settings.