http://www.blogchalking.com “Blog chalking" apparently uses this technique to map the blogosphere
to terrestrial geography. Basically, you enter geographical and
demographic information into the Code generator. It spits out a string which is encoded in an HTML tag that you put on your web page. You can then Google the string to find other blogs whose authors have similar geographic and demographic characteristics. So I could find out who has a blog in my town, for example. The Blog Chalk people claim that doing this also raises your profile in the search engines, though I have yet to find an explanation of why this is so.