I’ve just looked and noticed that oswd.org (Open source web design). They currently boast 715 free templates. In their absense several other sites have sprung up to fill the void they had left… openwebtemplates.com is one such recent entry. There’s also openwebdesign.org with over 1300 templates. There are several sites that seem to be mirroring the original list of zipped templates from oswd.org, but I don’t find any others with thumbnails, openwebdesign.org appears to have the complete list.