The way we did it before was to exchange addresses via PM's. That way, your address is protected from public view and you can exchange addresses with those you feel comfortable doing so with.

If you want to exchange postcards with someone just send them a PM asking if they'd like to swap addresses with you. I know some of us used our maiden names just for a little added privacy and/or protection. I haven't heard of anyone who regretted exchanging postcards and it seemed to be a fun thing for everyone. I think we sort of just all got busy last year with the holidays, etc. and it sort of just evaporated.

I found postcards at the Publix grocery store but I know others found them at rest areas and book stores. It's fun to get a card from someone else's home state or country.