rel="nofollow"initiative spearheaded by Matt and Jason at Google is a welcome step in helping webpage authors give semantic hints to search engines.
I first wrote about this in March 2003, suggesting a way to link while expressing endorsement, neutrality or approval, and cited some previous suggestions there. This became the Vote Links specification later, which has been supported by Technorati for a while, and it is great to see Google, Yahoo and MSN picking up on this idea.
Since Wednesday morning, the Technorati spiders have been respecting the
rel="nofollow"attribute on links, along with
rel="vote-against", excluding these links from Authority counts, and Cosmos searches (we've seen just over a thousand
nofollows so far).
I've taken the liberty of drafting a more formal specification for the nofollow rel attribute, and I trust we can submit this to a suitable standards body in future.
I'd also like to second Dave's call for a Spam Squashing Summit, as there are many other sources of spam in blogs and elsewhere on the web.