Alt-tab switches between applications, not windows. So when I need to switch between two different terminals, as I often do at my work, I have to use both hands: one for the Alt-tab to get the application list and one for the arrow-keys to choose the terminal window.
More information can be found at http://www.wired.com/dangerroom/2012/09/suicidal-drone-6-miles-away/
"Call immediately. Time is running out. We both need to do something monstrous before we die." -- Message from Ralph Steadman to Hunter Thompson