Via BlogHerald, an interesting post on understanding Technorati tags.
Technorati tags are a newish way of pre-classifying posts on a blog, in much the same way that del.icio-us and other "folksonomy" operations work. But they also have a secondary function in that they summon Technorati's spiders to your site to index the full post. This two-step, Ping and Go process is largely responsible for the perceived delays in the system.
A couple of other related articles, the New York Times has a new piece on folksonomy and tagging, and Darren wrote a short article awhile back for our Capulet Newsletter, including more resources on folksonomies.