Any good ideas or past activities you’re kids have been involved with that were successful?

My wife and I have typically had our kids spend their own money on certain wants they have. They range from 13 down to 5. This summer a handful of them want to do some worthwhile activities that cost a fair bit more than the usual toy they buy, so I’m looking for money making ideas. I grew up going door-to-door, so that’s where my head is at. Last year I had them sell some leather work/gardening gloves door to door because that’s what I did as a kid. It’s something unique and very useful, plus it’s easy to find a good quality product. We obviously like the work ethic and business acumen building that comes along with it all too.

Other ideas?