That's what happens on chat - someone wants to get a postcard and you decide to start a club. Rules are simple: if you want to take part, post here so that we all know you want to join. If you want to exchange postcard with someone, send her/him your snail-mail address by PM. You will get the return address through the same channel. Send a postcard. Wait. When you get the card - post here. Please don't post your snail-mail addresses here. Note to all interested: I am not treating this post as the final version, very likely these 'rules' will need some refining. However, in 30 minutes I won't be able to edit the post, thus we have to rely on good will of Mentors to do so.