During the summer between my Junior and Senior years of High School, I participated in UCSB's "Summer Juniors" program. This is basically a program where high school students are allowed to take up to 6 units of college work (at UCSB, of course). Technically, the people in the program were enrolled as freshmen.
While there, I took two classes. A computer science course that taught beginning "C" (the computer language) and a beginning photography class.