My ds loved Legos Mindstorms when he was that age - and many schools have teams for the Lego First League (sorry I can't remember the exact name!). If you could find him a team to join he might like that - although I will warn you, the league includes a component of research and presentation on a topic that's not entirely robotics-related, and most of the kids we coached in our group didn't really get into that, they were just interested in the robotics. BUT fwiw, there are a lot of kids who love it, and there are a lot of teams all across the US, and sometimes the teams are one of those places where you'll find a lot of GT kids.
My ds also really loved building things with his dad... who's an engineer. I have no idea how you could replicate that *but* if you no anyone who's an engineer maybe they would have ideas for you and might volunteer to mentor him on a project?
Model remote control airplanes (the types that you build from scratch and they actually fly) were also really interesting to my ds at 10. If you're not into it, there might be a club that you could find through a local hobby store where you'd find someone who could help him if he needed any kind of mentor for it.
My ds has also enjoyed programming - he learned SCRATCH and something else at his school, and did an individual JAVA course at home. He seemed to enjoy the classes at school where he had a live instructor more than the online computer courses, and I'm not sure why (or if it would matter to any other kid on the planet lol). He's a-ok with online work in general - he worked through ALEKS on his own for years and now has been taking CTY courses online and enjoying them, just didn't like the computer course he took (I can't remember what it was through).
Another idea is to check with your local universities and see if they offer any kind of science/engineering programs for young students.
polarbear
