I have recently been thinking about Steganography again and various carriers as well as applications. For those of you that don't know what Steganography is, it simply means 'hidden writing' from the Greek. Some examples of steganography are: tatooing the scalps of messengers and then waiting for their hair to grow back; writing a message on the wood of a wax tablet before pouring the wax in; 'invisible inks'; pin pricks above characters in a cover letter; etc. Basically, we have a 'cover', which could be an image, passage of text, etc., that we are happy for anyone to see and a message that we want to hide within it so that it is undetectable. It turns out that this last part is quite hard. Anyway, I thought I'd look at techniques to embed data within Twitter as it is popular now and people are starting to monitor it. Hiding within a crowd, however, is a good technique as it takes quite a lot of resources to monitor all activity on a service like Twit...