I know a bunch of people that I don't actually have current relationships with, so it's odd adding them as my "first" friends.. and it sucks trying to add strangers. How the hell do you get started and keep some dignity? :roll
i dont see why it would be odd adding them as your friends, it depends on how serious the social networking site is, like on business networks like XING i wouldnt do it but on facebook or myspace, go ahead!
btw i dont see the purpose in collecting friends but what you already do: talking and creating relations, there isnt more to it in my mind