My DS is now 16, and I've let him go off on his own for short periods on rides or to the arcade with a walkie-talkies and, more recently, a cell phone since he was at least 12. By 15, I was giving him a little more rope. Shortly before he turned 16, he took a friend, and they went many places on their own, including back to the DLH or DTD. OK -- so one of them did leave their parkhopper at a restaurant once, but they caught it quickly enough and were able to retrieve it. No harm no foul. I think they had a great time on their own, and I felt they were perfectly safe. In fact, I bet my DS would be a lot less interested in going back as often if I didn't give him some freedom. When my DS is not with a friend, he has a little more trouble remembering where we were supposed to meet, but when he's with someone else, they seem to help each other remember the instructions. As long as your kids are reasonably responsible, not only would I say it would be OK, but I'd recommend you give them a chance to hang out on their own.