CMS Area
Provides downloads of Postnuke themes and web templates but requires registration for access to download [Open Source, GPL].
Dezina
Offers the Dezina theme for a PostNuke system which is also used on the site as a demonstration of its look and feel [Open Source, GPL].
Envolution Themes
Demo PostNuke, XTE, Xanthia, Autotheme, PHPnuke, PHP-Nuke, Xoops themes all on under the Envolution Content Management Framework [Demo of Envolution Theme Drivers, Downloads are not activated solely a demo site].
PostNuke Themes
Official site offering new and current PostNuke themes. [Open Source, GPL].
Postnuke Themes at SourceForge
Provides a theme pack for PostNuke .64 and two new themes for PostNuke .71 [Open Source, GPL].
Psyx
Offers themes for PostNuke with the additional feature of an online demo of the themes applied to the current site [Open Source, GPL].
Tangant
Has a collection of themes for use in a PostNuke System along with some block modules [Open Source, GPL].
Virtual Infinite Pixel
Provides free PostNuke themes, templates and blocks. Commercial themes are also offered [Free and Commercial].