These kids are in 4th grade... why don't you stop and imagine for a moment about where technology might be by the time they are adults. I can imagine home automation might be something really cool by then. Tell them about the houses they might live in in the future. Consider brain computer interfaces... suggest to them that one day computers might be so small and invisible that they can talk to their friends across the world just by thinking it... I'm sure u can come up with some of your own grand ideas about where technology can take us. Make sure you throw some of that in. The kids are the future, the future is about hope.. give them some grand ideas.