Steve FranksHere's how Uber got its start and grew to become the most valuable startup in the worldverified_publisherBusiness Insider - Nathan McAloneFive years ago, a company called UberCab made a splash in San Francisco by letting you hail a car with your smartphone. Since then, the company, now known as Uber, has spread like wildfire through the globe. Uber currently operates in 58 countries and is valued at over $50 billion. But the road …