Kids, teens and adults are more inspired to tinker after they learn the basic framework of what they are tinkering with. Electronics and circuit sets are great, but it really helps to jump-start learning with demos or projects that are heavily documented in the box. After you get your bearings on what works and what breaks, you are more free to experiment and add your own ideas.
To that effort I'm working on a hackable alarm clock based on the Raspberry Pi platform along with several Adafruit/Sparkfun components. The idea is that we can build a customized, tricked-out bedroom alarm clock with some general off-the-shelf components to see how hardware and software work in concert to create something useful. After the project is done, I'm hoping its creators will feel inspired to rip it apart or build new features using the pieces.
I've already run these lessons with a few kids between the ages of 5 and 11, and it was pretty interesting to see what they found interesting. They all wanted to start playing music, but they celebrated being able to have whatever number they wished show up on the LED display. To simply type "77," hit "Save" and refresh the display was enough to send them clapping. They also spent a ton of time building their own enclosures out of Lego, designing the perfect case for their clock.
Right now we have made it to Lesson 6 (the AM/PM indicator), however I have only published up to Lesson 4. More are to come, and I have already found some refinements that need to be made in the previous lessons. The lessons are available at http://hackclock.deckerego.net/, the hardware project is documented on HackADay at http://hackaday.io/hacker/5116-deckerego, and the Python source code for the clock driver is posted on GitHub via https://github.com/deckerego/hack-clock. I will keep these sites updated as the project grows.
Let me know if you try out the project yourself. We are already making some fun hacks, such as using the LED display to show the answers to math problems. I'd love to hear what other people devise!