Get involved in academic research. You'll be able to use your skills, and they've usually got money to throw at talented young people. If you can find a local university with a Human-Computer Interaction Studies program, you can get useful UX experience, if you want to get into the big-boy numerical stuff, you can look at Physics or Engineering departments, I'm sure a Computer Engineering department would love to have you, the list goes on.

If you're not hell-bent on being a capital-E Entrepreneur at 16, why not step outside the web development box and hang out on a college campus where you might have some fun?

My 2c.