Start-up mania hits San Quentin prison as inmates turn entrepreneurs One by one, the entrepreneurs, clad in crisp blue jeans and armed with PowerPoint presentations, stood before a roomful of investors and tech bloggers to explain their dreams of changing the world. For these exuberant times in Silicon Valley, the scene was familiar; the setting, less so. With the young and ambitious flocking again to northern California to launch Internet companies, there were signs one recent morning that start-up mania has taken hold even behind the faded granite walls of California's most notorious prison. 'Live stream has gone mainstream. Mobile...