I guess if the President of the United States or a movie star is speaking at your college commencement you remember who they were and what they said- and if not, these days, you can always watch it on YouTube. Steve Jobs at Stanford in 2005, Ellen Degeneres at Tulane in 2009 were a couple of the famous speeches made in recent years. Some of the big ones for 2012 according to Hercampus.com are names you'll know and the graduates are sure to remember:

Barnard College- President Barak Obama. No matter where you stand politically, when the President is your commencement speaker, you remember that.

Princeton- Steve Carell. Whether you think a movie star is an appropriate choice or not, you must agree, it will be memorable.

Rochester Institute of Technology- Bill Nye the Science Guy. Probably a real thrill for the chemistry graduates.