Since kids spend a lot of time indoors these days, how about venturing outside? Take your son on a hike or bike ride along a nature trail. Or if you have more time on your hands, consider a weekend camping trip. Some outdoor adventure stores offer equipment rentals if you don't already own a tent and supplies. Out in nature, you can show your son how to fish, build a fire, read a compass and other essential survival skills.
Trapped in a concrete jungle? You can still have an outdoor adventure with your son, despite the urban setting. Set up a citywide scavenger hunt for him and show him how to navigate with street maps. A trip to the park for flying a kite or a radio-controlled airplane may also appeal to younger boys. Even a short ride on the subway or bus can be a great adventure in itself for younger kids. It's a great way to open their eyes to the diversity of people and their general surroundings.