Apple today announced that downloads from iTunes U have surpassed one billion. Originally announced as a partnership with Stanford University in late 2005, the service expanded a couple of years later before a dedicated app was released to leverage the iPad as a learning tool.

Senior vice president of Internet software and services Eddy Cue said it’s inspiring to see what educators and students of all types are doing with iTunes U. He said there are now iTunes U courses with more than 250,000 students enrolled in them, representing a huge shift in the way we teach and learn.

Cupertino pointed out that over 1,200 universities and colleges and 1,200 K-12 schools and districts play host to more than 2,500 public courses that teach the arts, sciences, health and medicine, education, business and more.

A general chemistry course offered at Ohio State enrolled over 100,000 iTunes U students in the first year it was offered. Professor Stoltzfus said the interest that his class receives from non-college students in overwhelming. He has worked with a number of high school teachers that are using his material to teach their own classes and there are even some retirees that enrolled simply to stay intellectually active.

Interestingly enough, more than 60 percent of iTunes U app downloads originate from outside of the US. This international reach is helping to give local educators recognition and acclaim in their field from teachers and experts around the globe.