A subject that's been intriguing me recently is that of secret messages! There are so many ways to hide text and images. Here are some different ways to conceal things.
Hide your messages as ink stains! You know those ink killer pens? Write over ink from a fountain pen, and the ink is erased! Normally, on the other side is a pen that can't be erased (or "killed"). Simply write your message or draw your image with the unkillable pen, then cover it with fountain pen ink!
To read the message, simply kill the ink, and the message will be clear to you.
Hide private comments as white board images! Simply write your message or draw your image on the whiteboard, then make the paintbrush really big and paint all over it. Then do some cozy little pattern over the top.
Nobody will suspect anything suspicious - unless they click the "Animate" link on your white board image and uncover the secret message!
That's all I can think of right now. Until next time ... drop me a comment! What ways of concealing messages do you have? Talk to me! Ciao!