Delivered on 25 April for Rotary Club, Tanglin Synopsis: The era of business plans and presentations to raise money for mobile-web tech start-up ideas is over. In Silicon Valley, the venture incubator, Y-Combinator led by Paul Graham together with the business angels there have crushed the old school way of building an internet start-up by three core concepts: agile, iterate & pivot. In this talk, we examine how these three core concepts are applied in practice by examining the case studies of the latest and hottest of start-ups in US: Facebook, Twitter, Groupon and FourSquare.