Most people have moved on from Last.fm, including its founders. But those very same founders are now back with a new site, Lumi, that takes Last.fm's core functionality and applies it to the entire Web.In essence, Lumi tracks all of your web browsing, in the same way Last.fm kept track of what you were listening to, and provides recommendations and more content based on your likes.
Recommendations sites are a dime a dozen, but this one takes care of the core problem, acquiring data, by simply requiring users to hand out their web usage.
No one has access to that data, it's only used to provide recommendations and only visible to you, the site says.
For now, Lumi is in private beta, but you can sign up for the waiting list. Once you're in, you'll get a browser extension that will keep track of your whereabouts and access to the site which provides the suggestions.