Using steganography in an existing image is so much more visually appealing than a QR Code. I'm puzzled as to why it hasnt taken off yet. Perhaps the whole idea is patent encumbered. QR Codes are bulky and ugly to look at. If my business card had my photo on it and my linkedin url were encoded in the photo, that sounds better in just about every way. Whats even better is a small, appealing logo could signify the presence of embedded information in the image.
This morning I thought it could be a killer app to have a wordlens effect in the image-code-reader app so that when one looks at the poster on the wall, the embedded URL would be "written" on the poster. Like Bilbo baggins looking "moon letters" on the map of Lonely Mountain. A royalty-free standard for embedding data into an image would be fantastic and create a spot for one or two "killer" mobile apps.