Making a drm free smart playlist in itunes

Here is a trick I figured out when trying to find what music I own could be played on a linux box. If you go into itunes and create a smart playlist (command-option-n) then add the single rule "Kind :: does not contain :: protected" then you instantly get a playlist of your library with the drm'd music filtered out. To make this a little more useful you may want to add the additional rule "Podcast :: is false."