While social networking sites already help users maintain connections with friends and interest groups, a recent trend in web services has been the growth of semantic technologies that connect people across different websites. New York startup AdaptiveBlue offer a service called "Glue," which uses semantic web techniques to understand the content of popular web pages that describe lifestyle objects such as books, music, and movies. It then lets you do many useful, in-context things based on that data, such as learn more about the movie or actors on IMDB, buy the soundtrack on Amazon, read the historical background on Wikipedia, and a interact with a variety of other sites and services.
Twitter, Facebook and LinkedIn have some new company. The Klout API is launching a new service to "sign in with Klout." Called KloutPass, it gives developers access to user influence data at the moment someone signs in. It also gives Klout the opportunity to be a stealthy player in the coming identity wars.