Then Opera does something actually quite cute with theirOpera Face Gesturesgag:
Looking ahead, we recognize the future importance of touch interfaces, but we believe that there is another input device that is already present in most new computers and it’s ready to enable a whole new way of user-interaction: the webcam.
Today we introduce Face Gestures, a revolutionary technology designed to make interacting with your browser easier and simpler on computers with cameras. Face Gestures lets you perform frequent browsing operations with natural and easy to make face gestures. By using an internal technology dubbed Face Observation Opera Language, we are able to recognize pre-determined facial expressions and match them to commands on the Opera browser.