Use your curriculum and lesson-plan building skills to help corporations create effective and engaging training curriculum. Ongoing training is an important issue at almost every major business.
Tutor individual children either privately or as a member of a tutoring organization. Skilled tutors can make an excellent hourly rate but are not stuck to a school schedule or class.
Work as a consultant to public school districts analyzing their curriculum and the effectiveness of their teachers. Calling in someone from outside the public school system can often help a school identify areas in which it needs to improve.
Write for an education magazine, blog or other publication. If you are adept at writing and well versed on your subject matter, you could make a career out of writing for educational publications.
Build your own set of courses on a particular topic that you enjoy, and then try to market it via the Internet. For instance, many people want to learn a new language or gain better computer skills; If you can create courses that help, you may be able to sell them and create your own business.