Collaborative Filtering for News
Findory.com is a news site with collaborative filtering (see an explanation of the term in here), serving aggregated news based on your interests.
When you return to the site after reading a news story somewhere, the listings have changed, and the headings that have been generated by the filtering algorithm are marked with a ‘personalized’ tag. It’s a cookie-based no-registration service which is new in this genre. Very nice.
Weinberger does some guessing about how the filtering algorithm works.