Neil Young talks model trains with David Letterman. Young isn't just a model train enthusiast, he's also an inventor. From Dangerous Minds:
Young first created a research and development company, Liontech, to help the storied Lionel, LLC train manufacturing company, founded in 1900, create model trains with sound systems and control units. Young then became part owner of Lionel, along with an investment company. It was Young's designs and inventions for Lionel that helped to bring the company out of bankruptcy in 2008. Young's first train-related invention was a control unit, the Big Red Button, that enabled his son, who has cerebral palsy, to control the trains.