The Digital Inspiration blog hits upon a pretty nifty use of a file-hiding technique we’ve shown here before, to share MP3s with a select group of friends, or even embed a related sound file inside a photograph. Using Flickr’s easy photo-sharing and a command-line trick, you can create a JPG file that anyone can download and, once renamed as a .mp3 file, plays in any music player. For more file-hiding fun, check out our feature on easy steganography tools.