Example sites that use LinkedIn's API equivalent of 'Facebook Connect'?

Anyone know of any example sites that use LinkedIn's API as sign-up/registration service... similar to how 'facebook connect' is used. Can't seem to find many, if any, examples out there. I wonder why. Must be开发者_开发技巧 a good reason for the lack of sites adopting this method of authentication.

Not exactly a web site in the sense how you mean it, but the mobile application Socially launches LinkedIn's authentication page in the mobile browser to authenticate using the service with the application.