A super-simple plugin that activates a CSS stylesheet to render your WordPress site in a way that would feel almost at home on a Mac Classic running Hypercard…
Download at Hypercardinator
Hypercardinates your site using css and webfont – thanks to Giles Booth for releasing the Chicago-like webfont ChiKareGo via a Creative Commons license at http://www.pentacom.jp/pentacom/bitfontmaker2/gallery/?id=3778
The plugin also tries to force images to render in Hypercardesque high-contrast black and white (but some images sneak through – namely thumbnails for embedded videos etc.)
It should work with any theme.