While I would love this, there's no way I could convince more than one or two of my friends to do it :( >It works inside Facebook, with who's already your frie

While I would love this, there's no way I could convince more than one or two of my friends to do it :( >It works inside Facebook, with who's already your friend. It just works. Wording is a bit confusing there. How difficult is it going to be to exchange keys with my friends?