I found a pagerank spam website, designed only to raise the pagerank of itself and other spam websites this evening while researching banking blogs, as I contribute to Informed Banking Blog. This practice is annoying as email spam, if not more. Surfing the internet that much more of a pain, and quality blogs that much harder to find.
I expect this practice to erode Google's index if they don't implement filters, as it really pushes the onus of filtering and ranking webpages back onto human editors. This fact is apparent with Google's coop, which provides humans the ability to be their own editors to some degree.
I'm posting a webshot instead of a link to the site to prevent a trackback.