I love this thread. As one who was hooked into cycling by my 14 y/o son, it has *totally* changed our lives. Everyone in my family rides now. Even though said son is now 28 and only is commuting to classes right now, I always feel like I owe him big time. He was very responsible with all of his bikes and learned a lot about mechanics, too while racing.
And on the "better than playing video games," I am working with a family where one of the biggest issues is the 12 year old boy being addicted to video games. He doesn't have so much of a problem when it's not winter, as he does soccer and can be outside, but the family can't afford winter sports. We've made a structure for rules around this and dad is the one who caves. Last week, I had the kid brainstorm a list of activities he likes, to combat boredom. We went from "nothing," to a list of maybe 15 things. I told him in a couple of weeks, I would bring my bike and we would ride. He lives about 2 miles from the orchard where we make a lunch stop on the hilliest local ride we do .