Hiding files in JPEG
Posted by Circuit Negma on December 22, 2007
I never knew this was even possible:
Step 1: Get yourself a nice JPEG image.
Step 2: Archive the files you want hidden into a RAR archive
Step 3: Open the command prompt and merge them like this:
Where image1.jpg is the original, something.rar is your archive of files, and image2.jpg is the final image.
For a more thorough writeup: