Here's another interesting new site that builds on the "trusted friend" model. It's called ReviewParty, and - as the name implies - users get to write and post their reviews of current media.
While Epinions tried to be a do-it-yourself Consumer Reports with reviews of everything under the sun (and fails, partly because of that), ReviewParty is more tightly focused on books and music (at least for now). Each review is, of course, linked in to that item at Amazon.
There is a revenue incentive for reviewers. Half the time your reviews will show your Amazon associate and Google AdSense codes and half the time it will show their codes. My guess is that after the beta period the percentage of ads that are "mine" will go down. That guess is based on my experience with sites that launch promising an incredible income for the users, then realize that they can't support themselves with that level of generosity.
Still, it looks interesting. I've signed up and posted a review of the new Ray Davies CD, Other People's Lives. The site is brand new - I think my review was only the second one posted. We'll see where and how it develops.