During a quick 10-minute presentation on stage, Amit Mital, general manager of the Live Mesh team at Microsoft, showed thousands of people a video of a boy jumping into a pool. Though not even in product form yet, Live Mesh wins the coolest-product award for its potential impact on the millions of people using Windows on desktops, laptops, cameras and smart phones all over the world. It also has the potential to choke Microsoft if it fails, as Google rolls ahead online.