Steganography - The art of writing in cipher, or in characters which are not intelligible except to persons who have the key; cryptography.

I recently came across a group of articles that discuss Steganography by Corinna John, age 24, from Germany. I am not easily impressed but this girl is a heavy hitter. She is an advanced programmer who has spent a lot of time with this subject of Steganography,Cryptography and Image manipulation. She is very knowledgeble about imaging, AVI, pixel manipulation etc.
Here are a few titles:

1)  Hiding messages in the Noise of a Picture
2) Hiding messages in .NET Assemblies
3) Hiding Data in Wave Audio Files  etc.

She is a person that should be on the Microsoft training circuit and who deserves recognition in the .NET community.

Check her out.
http://www.codeproject.com/script/Articles/list_articles.asp?userid=475133