http://www.w3.org/2001/sw/ is Tim Berners-Lee on the subject of the Semantic Web, including group culture reinforced by the same language. Interesting to read this the same day as someone's Unix answer to the weirdness on Macs from MS characters, http://www.fourmilab.ch/webtools/demoroniser/ that Dan Gillmor was bemoaning.
http://tagsonomy.com/ is the first blog I've seen devoted to metadata, populist-style, not academic.
A comprehensive list of articles on all aspects of usability:
http://www.spingroup.com/htmdocs/resources/index.php