We are the biggest examples for our children, and damned TV's and computers can be addictive. I remember sitting in front of the TV, on a Saturday morning, and having my Dad come ask if I wanted to go to the hardware store with him. A quick "No, thanks" (hey, these shows were only on once a week) was soon followed by the thought of all the different neat things to look at and his interesting conversations with the propieter would inevitably have me barreling out of the house as he was backing down the driveway. I would also be "torn" from the tube due to curiousity of what he was doing in the garage, driveway, basement or yard.
We can't force any one to do anything, but we can lead by example.
I've been asked many times why I take on such large, long term projects, my response (stole it/LEARNED IT from my Father) "Beats watchin' TV".