Apple slipped in a quieter announcement today amidst the iPhone 4S chaos: The launch of a new app called Cards, which lets you create a real, physical card from your iPhone by taking a photo on your camera and choosing from a simple selection of 21 different designs. Then Apple mails for $2.99 (U.S.) or $4.99 (elsewhere). You receive a push notification directly to your iPhone as soon as the card arrives at its destination.

What’s the Point of Sending a Paper Card?

The Cards concept is not new, actually: San Francisco-based startup Sincerely launched the Postagram service in April 2011, which enabled users to take photos using Instagram (they’ve since expanded to Facebook photos and an Android app), and sending them as postcards for $0.99 a pop. Postagrams can also include a personalized 140-character message – you know, the same length as a tweet. Similarly, the iPhone app Postcard on the Run, launched in 2010, does the same thing, helping you to create postcards from photos you snap on your iPhone; it similarly costs $0.99.

Ideas like this that let people feel creative, and that dub themselves “new technology, delivered the old fashioned way,” as Postcard on the Run’s tagline states, have a certain charm.

Since Apple broke the news about the Cards app, shares of American Greeting Corp., American Greetings, Carleton Cards, and others have slipped, according to reports on The Globe and Mail. But then again, shares of Apple Inc. also dropped after the iPhone 4S announcement.

Regardless, Apple’s customers are hungry for apps – they’ve downloaded more than 18 billion apps at the pace of “more than one billion per month,” explained iOS SVP Scott Forstall at today’s iPhone 4S launch. It’s pretty normal for Apple to take shots at PC and Android apps- but now they’re aiming to conquer more traditional paper greeting card companies, too.

Cards will be a free download app, launching on October 12 with iOS 5.