"How will you be of service to your nation and all the world?".."One: What is the nature –– fundamentally –– of the 21st century world? Two: How would you like to change it? How would you like to leave it for your children and grandchildren? Three: What must be done to affect those changes? And four: Who's supposed to do it? Especially, what are you going to do?"
- President Clinton at Princeton University's Class Day Ceremony
“I hope that you will contribute in some measure to economic progress, whether in the United States or elsewhere; and I hope you find some measure of financial reward. But the world has a great deal more to offer than money, and a key question each of you will face repeatedly in your lives is how to use the talent and education that you have been given and the knowledge that you have attained.”
- Ben Bernanke, Commencement Address at MIT
“There is much more to be done, too, in truly integrating Harvard with the world. Students from abroad coming here to study return home changed people, and those they meet here are changed by them. Remember a few years ago the rescue of a doomed Russian submarine crew? This rescue was only made possible by a contact between a Russian admiral and an American admiral - two who never would have communicated if they had not met in a Kennedy School joint military program.”
- Harvard University President Lawrence H. Summers, Commencement Address
“All of which reflects one of the many things that bothers me about our educational system. Considerable parts of it appear designed to teach people to pretend to intellectual tastes and knowledge that they do not possess and that there is no good reason why they should possess.”
- David Friedman (son of Milton Friedman) – he introduces himself as an academic economist who teaches at a law school and has never taken a course for credit in either field.

Andrew Samwick has more on Summers speech;
http://voxbaby.blogspot.com/2006/06/commencement-at-harvard.html