fidipidi is a new Facebook app that extends the usefulness of Facebook by letting users design, customize and send actual physical greeting cards to their friends and family via snail mail. The app lets you choose from a selection of cards, ranging from Birthday Cards, to Just Because cards. Add a message, a photo and text, and then fidipidi will print and mail the card out for you. Obviously this is a much more personal gesture then just sending an online greeting, but it has the benefits of being just as easy as sending an online greeting. fidipidi officially launches tomorrow and the service will not be free. However, the first 15,000 people to sign up and use code “1stCardFree” will be able send their own cards for free.