Reading Reddit, I stumpled upon this article explaining AES using stick figures. I found it so interesting and nicely drawn, that I think you should have a look at it as well. Of course, it is not cover all the "dirty" details but it makes some relevant observation points.

So here it is: http://www.moserware.com/2009/09/stick-figure-guide-to-advanced.html

Last Thursday i got my Free Software Foundation (FSF) membership card, which is a credit card sized USB drive. It looks like the following:

The other day I stumpled upon a wikipedia site describing the art of Steganography. And as it says: "Steganography is the art and science of writing hidden messages in such a way that no-one apart from the sender and intended recipient even realizes there is a hidden message. By contrast, cryptography obscures the meaning of a message, but it does not conceal the fact that there is a message. Today, the term steganography includes the concealment of digital information within computer files.