30 years ago when an educator was to teach a new course, they would prepare the lectures by going to the library, reading books and journals. Then we would go into the classroom and use a chalk board for our graphics.  At the end of class the board would be erased, and our lectures would fall to the floor as dust.  PowerPoint provides a very powerful tool that has changed all our teaching. Most people think the power of powerpoint is in the presentation where it is pretty, plays music, shows video, etc.  The is not the component that will change all of education, rather it is PowerPoint on the web. For the first time we are able to save, and share our lectures for our teaching. We recycle lectures rather than destroying them at the end of class.  This reduce preparation time for experienced teachers, and makes for better lectures as the content is prepared by an expert.  In resource poor environments, it has been impossible to teach well as much of the materials are 15 years old. However, now Dr. Holdren’s AAAS lecture could be used in Zambia minutes after he present, thus we can markedly improve global training merely by sharing our PowerPoint presentations.