SiteReviews.org supports hReview. I think.

http://developers.technorati.com/wiki/hReview A clever idea for distributed reviews of things. Well I think the reviews at SiteReviews.org (on the main HTML pages) follow the standard. Bits of it confused me though. Either way it meant I finally made the site XHTML compliant. Although considering how much user-contributed stuff there is on there (like most of it) various pages will undoubtedly fail… microformats, hreview