Human brain is a smart machine that is capable of generating amazing ideas; an apparatus that stores diverse solution to many complicated problems.
Unfortunately, smart ideas sometimes are needed not for technological advancement, but for survival in presence of terrible illnesses or disabilities.
Jean Dominique Bauby was a French journalist who was diagnosed with locked-in syndrome after having a stroke. He was paralyzed physically, but his fully functioning mental abilities were still inside his body that was no longer governable. The only physical ability that he could use to communicate with people was the ability to blink with only his one eyelid. But being imprisoned in his own body was not a reason for Jean-Dominique to give up. He used an idea of partner-assisted scanning in order to express himself; he even wrote a book by dictating every single letter and word to his assistant using the blink of his eyelid every time that the letter shown by his assistant was the one he wanted to use. In this, a brilliant idea of analyzing letter frequencies in particular languages were very useful (another smart idea!). Instead of using the regular alphabet (French), letters for dictating were used by their frequencies: the most used letters come first, which made the job easier and faster.
Note: The book that he wrote is called "The Diving Bell and the Butterfly" and there is also a movie based on the book.
Letter Frequencies are very interested to analyze. There are many reports that give approximate frequencies of letters based on analysis of samples of random documents for particular language. For example, the analysis of random 40 000 words in English was reported by Cornell University here.
