I believe that our children will do whatever us parents show interest in doing. I'm guilty of allowing my children to be couch potatoes...not as bad as some, more than others I'm sure. The bottom line is, my kids will throw down the controllers when I say, "Hey, want to go fishing?" "Want to play catch?" "Want to go for a walk to the convenient store?"
I think the busy-ness of our lives today leave us spending less time doing things with our children so in many cases they just play video games or watch TV because...what else are they going to do?
It has to start with the parents, myself included, putting down the grind of life to spend time doing things with our families. It strengthens the bonds of the family and is really more healthy (mentally and physically) for us all. Taking a walk is free, geo-caching is free, playing catch is free...don't let money be the factor. Our kids don't care about it as much as we do.