I love this idea. It's done a teeny tiny bit in the form of work experience, but actually we should make a scheme where workplaces get some kind of incentive to let the kids come and hang around, maybe even do some work depending on what it is.

I would sprinkle this around the school calendar so that you had a few weeks a year where you could sit at various places of work and see what was going on, instead of little weeklong academic breaks plus a mega long summer holiday. Not everyone loves the academic side of things and this could be a good break, plus it might provide some motivation for the question of "why am I learning this" that everyone has at various points in their education.