Except that's a thoroughly one-directional approach. How can I log in to Facebook with an external identifier, without having a Facebook account? How can I ad

Except that's a thoroughly one-directional approach. How can I log in to Facebook with an external identifier, without having a Facebook account? How can I add someone on Facebook as a friend, while maintaining my identity on another site? Until it can accomplish those basic things, it's less than a solution.