In the 1950s and 60s chemistry sets were common presents to encourage an interest in science. You couldn't sell one like the old ones these days as many of the chemicals and experiments are now considered hazardous. And while some of it was interesting, much was misdirected - I never enjoyed mine, although there were other science and engineering kits.
A reasonable question is what could be done today. Greg points out a competition aimed at discovering just that. I sat down and thought of about twenty rough ideas in a couple of minutes. This seems like rich territory for Kickstarter funded operations. There is a clear need.