Isn't Cub Scouts a great program? We've really enjoyed it. A little un-asked-for advice on the martial arts program:
Shop around. We had originally planned on a Karate place near our home, but asked around, and decided on the less-convenient TKD place. We found that most of the places would give the kid a free lesson so he could try it out, and they all offered a short-term introductory schedule/price. FWIW, my wife is taking TKD with him, so it's become a family activity. Also, be prepared to shell out a few bucks. None of the places we looked at were cheap.
Yeah--we shopped around and found a program we liked. It's being taught through a local church and the cost is only like $25/month or so. Very cheap. Our main purpose is not necessarily to learn the actual martial art, but to instill a sense of discipline and also give him a chance at physical fitness and improve his general coordination. (Some physical setbacks--not really problems, but enough to go slower/different routes than most others).