Amateur Radio is a great opportunity to get involved with a variety of activities centered around wireless technology communication. It does require a license issued by the Federal Communications Commission. Equipment required ranges from built from scratch to off the shelf radios. Activities include casually talking to others worldwide, emergency communications during disasters, storm spotting, contesting, talking with the International Space Station, and working with wireless experimentation of all varieties. There is no age limitation and also a tremendous amount of resources are present on the internet to assist with your questions and activities.
For more information goto www.arrl.org or How To Become A Licensed Amateur Radio Operator