Posted this earlier this week on RS. Might be of interest to some of you.

Volunteers Needed to Manually Classify Web Spam, Research Project from Universita’ di Roma “La Sapienza"

"At the Algorithmic Engineering group at Universita’ di Roma 'La Sapienza', we are currently building a reference collection for testing Web Spam detection algorithms. While similar collections for research on e-mail spam filtering exist, there are no publicly available collections for testing Web Spam detection techniques. This collection will be freely available once it is completed. We are currently tagging a large subset of 8,000 .UK domains."

More info and links here:
http://www.resourceshelf.com/2006/07/12/volunteers-needed-to-manually-classify-web-spam-research-project-from-universita-di-roma-la-sapienza/

and

http://aeserver.dis.uniroma1.it/webspam/