Earlier I wrote about Steganography, also how data/messages can be hidden in image files in these posts :
How to hide files in JPEG's
Steganography app hides a messages in plain sight
today i find this article on lifehacker, It discusses some windows tools ( Hide in Picture ) that can be used to hide data in images.
Other free Windows tools offer more filetype support. wbStego can encode and decode files in PDF's, HTML files or bitmaps. mp3stego embeds text inside MP3 files (command line and GUI interface available.) Here are more Windows stego software options [via Webby's World].Read More >>