What age would you allow your kids to go off without you at WDW?

[slzer0]

I think a lot has changed since cell phones became commonplace.

Think about kid field trips, the students go off in groups, although they wear neon identifying shirts usually. These trips are normally 8th grade.

Depending on the kid, I'd say 14 but only for short periods of time, ie, one ride and come back.
And not just one kid. Safety in numbers.