Ever since the announcement on the Google Blog and more recently Yahoo's announcement that they've enhanced their support for it, I've been meaning to play with the X-Robots-Tag header. This HTTP header allows you to do what you'd normally do in a robots meta tag, in an HTTP header, which has some pretty cool appliances.

They "invented" blogsearch, and did a LOT for the webdevelopment and blogging community. Now Technorati, it turns out, is working on the microformats search I asked for only two articles ago (it was there before that, I just didn't know about it)... Check it out in Technorati's Kitchen.

Imagine, you can type in a query like "joost de valk class:vcard" and Google comes up with my contact page, because that has a vcard class in it's markup, the main class of the hCard microformat. This was suggested today on the uf-discuss mailing list, a mailing list I've been lurking on for quite a