Reporter John Markoff recently rode in a car that merged into heavy traffic on Interstate 101 in Silicon Valley, left a few exit ramps down the road and then negotiated city traffic through the city of Mountain View, stopping for lights and stop signs. It was no big deal except that nobody was driving. While Silicon Valley's been focusing on social networks and digital movies, Google is busy developing a car that's driven by complex robotics. Markoff wrote about his experience in the New York Times.