One of the reasons that I am so excited about innovations in the mobile space is clearly illustrated by this video describing a new application for the Apple iPhone.  It is a relatively simple application that measures your heart beat based on the sound of your beating pulse picked up by the microphone.  The excitement is in the possible future applications.  Today our medical system is completely reactive – it only shows up for work when there is problem.  Imagine how ridiculous it would be if airplane mechanics only showed up for work when a plane fell out of the sky.  Again and again you see that one of the greatest determinants of whether a disease is fatal or not is how soon it is detected.  We need to have a pre-emptive health system that uses technology to monitor our well-being all the time.  The mobile phones of today are, as is often said, more powerful than the computers of the last decade.  There are 3 billion of these computers scattered around the world and 1 billion extra are added every year.  These billions of cellphones represent billions of sensors that can be used to keep track of the vital life signs of billions of human beings.  Its possible to design applications to receive all of this data and to separate it into normal and abnormal indicators.  Those in the abnormal range can be emailed a message directing them to visit their doctor.  The data excerpt that prompted the alert can be emailed to the doctor.  I recently read of an application that uses the motion sensors in thousands of Apple laptops in California to detect earthquakes.  The vision is to take this networked data and create alerts that will immediately instruct public transport vehicles to reduce speed and come to a halt.  With sufficient sensors, joined together in a single network, the possibilities are fantastic – we can achieve early detection of pandemics, expose the illegal exercise of state power, provide tele-medicine services and in general apply the massive computational power of the cloud to any local issue.