Was doing some competition analysis earlier tonight, looking at backlinks for the #1 in a relatively competitive niche. I did a double take because a TON of the indexed links showing up were internal links, meaning the site linking to itself. After the initial WTF wore off I looked again, and realized the indexed backlinks were coming from the non-www version of the site, making it a totally different domain as far as SEO value is concerned. I'm vaguely familiar with the whole canonical link issue and how this can harm your SEO, but these guys have used it intentionally to great effect. I may try this out on a site or two myself and see how it works, anybody else who's done this glad to hear your experience, anybody else who tries it now definitely report back.