theodp writes "At some schools, a teaching load of five courses every academic year is considered excessive. But Sal Khan, as an earlier Slashdot post noted, manages to deliver his mini-lectures an average of 70,000 times a day. BusinessWeek reports that Khan Academy has a new fan in Bill Gates, who's been singing and tweeting the praises of the free-as-in-beer website. 'This guy is amazing,' Gates wrote. 'It is awesome how much he has done with very little in the way of resources.' Gates and his 11-year-old son have been soaking up videos, from algebra to biology. And at the Aspen Ideas Festival in front of 2,000 people, Gates gave Khan a shout-out, touting the 'unbelievable' Khan Academy tutorials that 'I've been using with my kids.'"