When are kids ready to camp?

Yes, I was thinking of this as in going on their own to summer camp for several days. I know it sounds like fun to Ian, but the only place he's ever really spent away from home was his grandparents' house or next door (where he could walk home if he decided). I think I was around 8 or 9 when I did my first Girl Scout overnight at one of the local camps. I really can't remember, but I think that age is right.