The current keyboard layout, called the QWERTY, was developed over a hundred years ago by typewriter inventer C. L. Sholes. It was chosen over the obvious alphabetical order because the old mechanical typewriters used long bars to print the letter on paper, and these bars would get stuck if the typewriter was typing English words very quickly. To reduce the bar clogging, Sholes placed letters that would be used together often as far apart as possible, like the letters "T" and "H".

And since that day we have been stuck with this layout, phasing it out would be too difficult since we've been used to it for generations.

You can get more information on this subject at Darryl Rehr's amazing resource, called The QWERTY Connection.

Question from: Zuhair