-- "He teaches millions of students a month, yet none of them has seen his face. Sal Khan is a disembodied voice on the Internet, but his teaching method has become so effective that he may be the future of American education. Dr. Sanjay Gupta speaks to Khan and to educators who use his popular educational website, "Khan Academy
," for a 60 Minutes report to be broadcast Sunday, March 11 at 7:00 p.m. ET/PT. Watch a preview above."