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.
For the past few months, the API of microblog site Twitter has been used as the basis for many popular and creative mashups. Now Facebook, with the launch of its highly anticipated Open Stream API, is attempting to gain some attention as a platform for social networking applications.