[nfc]

I was thinking something similar recently, and I also believe it's an idea worth exploring. Something else to add to this conversation. There's an obvious difference between two cases in which a trusted person trusts a url:

1) Single contributor website (blog, personal page...): It seems that we could spread the trust the whole website in the algorithm (at least more than for the next case)

2) Multi contributor website (forum, newspaper): It seems the trust should be given at an URL level

Something worth delving into if we are designing this trust based search engine in real-time here at HN ;)