autorave/entrepreneurship

While their peers were out making trouble, these young achievers were making bank.

Forever in search of the secrets to entrepreneurial success, we peeked into the inspirational lives of five whiz kids who built million-dollar enterprises before the age of 20.

They partnered with friends, siblings and mentors, or did the work on their own. Three are from the U.S., two from the U.K. All started at age 15 or younger--and one before he broke double digits.