Admit One Security already does this as a part of their keystroke dynamics tool. One interesting thing they do with it is to use key strokes to see if users are

Admit One Security already does this as a part of their keystroke dynamics tool. One interesting thing they do with it is to use key strokes to see if users are sharing passwords for subscription services. http://admitonesecurity.com/keystroke_dynamics_advantages.asp http://admitonesecurity.com/keystroke_dynamics_advantages.as...