Brigham Young University (BYU) has just begun its open content courses. They are much like the courses that MIT has been offering for a while. You don’t get credit from the University, but the courses are complete, mostly taken directly from courses taught regularly at the university.
BYU’s has only six offerings at the moment. They are running it as pilot program, but they significantly include three courses for high school students in addition to the three college level courses.
High School Courses