I think of the term "Boy Scouts" as shorthand for a whole bevy of youth organizations with an outdoor activity orientation. If the Boy Scouts are not one's cup of tea (for whatever reason) there are a lot of other (more obscure) alternatives (google turns up many many results).

At the 30,000 foot level for a gifted kid, a group (like scouts) with a range of ages and a lot of flexibility in terms of activities could be very positive (provided there is good adult leadership at the local level).