The pencil was, in its day, a disruptive technology. When the little pink eraser on the end was introduced it had educators throwing up their hands. Now, they said, no one will think before they write. The pencil is also an incredibly sophisticated tool. It took more than a century to perfect--Thoreau's family was a player in the pencil wars of the early 19th century.

Yet, no one notices pencils anymore. They are a great example of the successful integration of technology in education. (By the way, no one I know considers correlating pencils to test scores as they did in this misplaced critique in the New York Times: http://www.nytimes.com/2011/09/04/technology/technology-in-schools-faces-questions-on-value.html?pagewanted=all) The marks of this success are ubiquity and invisibility. A quick check on theses two scales let's me easily gauge the success of any school's technology program, however sophisticated the devices or applications they roll out.