Justin Henry is always kicking my butt because I tend to do stuff like this mainly in facebook (though some in twitter) which he describes as sort of “anti-social” social networking. I agree with his point, but I tend to be lazy, and there’s no good way (yet) of moving contacts between spcific instances of one’s social network. (Le affaire Scobelized shows how not to do this.)

Joi Ito does something a tiny bit like this with his faceroll and flickr accounts – “people i’ve met recently” – and though it is more open than facebook, it is still somewhat ad hoc.