Re-reading my previous posts it occurs to me that I was assuming that spending time with my family was taking time away from doing cool hacker stuff. I've missed a trick there. What I should have been looking for was the win-win. If the things you do with your kids are cool hacks at the same time then the hours are not zero sum. So, shifting focus, my search changes from looking for ways to hack in the spare moments around the kids to looking for ways to hack with the kids.
What would constitute a hack with the kids? Well it has to be something to do with problem solving, being creative, and getting immersed in a topic. The difficulty is finding the topic. Its got to be something where both me and my kids are interested. It seems patronizing to get the kids to repeat experiments out of kits without some wider motivation.
So that's what I'm going to try to do. If you have an idea for a topic then post a comment.