I don't have kids, but I grew up going to day camp every summer starting when I was 5. We were responsible for our own money, and our own stuff (bags, etc.) for all activities--skating rink, bowling alley, movies, etc., as well as theme park days. At 7, we were allowed to roam the parks on our own all day, just meeting up with the counselors by the buses at the end of the day. So some of the ages people are suggesting for simply carrying their own stuff while accompanied by parents kind of blow my mind. That said, all of my experiences were day trips. So I'm not advocating giving a 5 year old all their spending money for the week or anything. But I think if you divide up the total amount of money by the number of days, and give each kid one day's worth in the morning, it's not a huge risk. And if they lose it? Valuable lesson. I'd also let them carry low-dollar personal items like sweatshirts, water bottles, rain ponchos. Yes, carrying a bag, storing it on a ride, and retrieving it afterwards is hard. But it's a skill to learn like any other, and you can help out for the first few rides...gentle reminders of where to put stuff and when to get it back out.