Betapad is an interesting early stage product and iOS app available in Japan. Essentially what you do is draw on a pre-made card, take a picture of it using the betapad app, and it automatically goes to your social network stream(s). It does get a little more complex than that by using a machine readable medium that lets you mark off some options. You can share to Twitter, Facebook, or both, as well as select coloring options if you choose (red, green, or blue). The corners are marked, for what I believe the reason is, to ensure the correct proportions if the image is taken at a slight angle.
I like this concept and it could be a good business model if it catches on and people have to buy the cards. To do that the cards would need a unique identifier to ensure one time use otherwise users will just copy or scan a card to make their own. It may be easier to charge for the app and email the printable template to new users. But, I digress.
The demo video below is a bit light on the details and I had to do some translations to figure out what exactly was going on, which was mentioned earlier. Also, that yellow card is a demo/learning card; the cards you would use are all white except for the marks the app needs to see. When you install the application you link your social accounts so that they stand at the ready depending on how you indicate your betapad drawing to be shared, if at all.
Have you see anything like this available in the US? Add sharing to DeviantART, Pinterest, Picozu, and other networks and it will be a knockout for a lot of artists and doodlers. I think it is a very effective way to digitize and share artwork. CENDO has done an excellent job with the design!