Things my son really liked at 10:

Scratch http://scratch.mit.edu/

Minecraft https://minecraft.net/ (if he has XBox and an XBox live account, he can work with his friends to create things together)

Other ideas:
Remote control kits for planes, cars, etc. The planes were the real hit, especially the ones they had to build and wire
Lego robot or other robot kit
Home weather station




~Lisa
http://www.lisaabeyta.wordpress.com/