The friend graph lets developers explore connections between people. That's not enough, according to a new service that debuted at SXSW. It uses the status updates, interests and other data--currently just from Facebook--to determine a personality type. Whit.li calls the resulting information the "psycho-social profile." From that, developers can compare users for different types of compatibility using the Whit.li API. The service could potentially fuel a entire breed of "AirBNB for {blank}" type of apps, among other use cases.