My lab has just released a beta of iCandy, an application for Mac and PC that lets you associate an image and a two-dimensional QR bar code with any iTunes song, YouTube video or Flickr photo, and to print them out as postcards, business cards, posters or photo albums. Then you can just hold the barcode up to a webcam to automatically bring up the photo or play the song or movie.
The app itself is pretty cute (we’ve been using it internally for a few months now) and they’ve recently set up a community network site for sharing your playlists and media pics with others too. The online Flash-based version seems to be broken at the moment, but check out the app.