August 9, 2012 by Volamoot at Mashable!
Originally started as a hackathon project, the feature allows Facebook users to send any of their own photos to friends. You won’t be able to send public photos or photos from pages.
Just like a traditional postcard, the photo will be displayed on the front of the card, and you can type a personalized message to your friend on the backside. Postcards will allow you to type in your friend’s address if you know it, or ask him or her for their physical address is you don’t.
posted by Mashable from http://mashable.com/2012/08/09/facebook-postcards/