Update: Against Googles Methods

As previously mentioned in GoogleBlog: Preventing comment spam, the search engine built up a major cooperation with various blog hosting providers. Nevertheless, it appears to be a neat trick by Google to establish a new content-filter only to recognize websites as websites or in specific as weblogs. I cannot advise to integrate the rel=“nofollow“ attribute to any blog software as it clearly identifies the majority of weblogs. It would only grant Google the perrmission to recalculate the pagerank for paying customers – to raise their pagerank and lower the pagerank of any weblog.
I decided to implement a special CSS snippet by Phil Ringalda to lure everybody on any rel=“nofollow“ link:

a[rel~="nofollow"] {
  text-decoration:blink !important;
  color:lime ! important;
}