When pollster David Kinnaman went to college two decades ago, his Generation X life was surrounded by electronic screens and all the gadgets that connected to them.There were TV screens, movie screens and new computers, some of which even had speakers. There were VCRs, CD players, cassette recorders, video cameras and other cool devices. The hottest trend was "email" that allowed students to do something Baby Boomers could only dream about -- send private, instant messages to friends in nearby dorms or around the world.Today, all those devices have evolved into one life-changing screen carried by millions of the so-called Millennials – the smartphone.