Interestingness is a great name for a ranking algorithm. It's what Yahoo's photo-based social network Flickr uses to show which images the community finds the most "interesting."
Techdirt considers the impact that a couple of recent Yahoo patent applications filed for in February, and published last week (which I wrote about at SEO by the Sea), might have upon the growth of social networks. They reference the thoughts of Thomas Hawk, CEO of Zooomr, who weighs in on the topic in Should Yahoo Own Social Search and Rank in a Web 2.0 World?
We've seen the major search engines compete with each other in the face of patented algorithms, following their own paths to returning relevant results to their users. Social networks shouldn't find interestingness to be an impediment to letting their communities decide together what is interesting or not. Hopefully these patent applications will inspire other social networks to follow their own paths, too.