Previous commencement speakers at Harvard University:

Robert Rubin, former U.S. Treasury Secretary
Alan Greenspan, chairman of the Board of Governors of the Federal Reserve System
Mary Robinson, the United Nations high commissioner for human rights and former president of the Republic of Ireland
Madeleine Albright, Secretary of State
Harold Varmus, director of the National Institutes of Health
Will Ferrell, Christmas elf, frat guy, and school cheerleader
Conan O'Brien, visionary of the Springfield monorail and prognosticator for the Year 2000