Barack Obama gave a heart-felt, thoughtful speech on Sunday, as he filled in for Sen. Edward M. Kennedy during Wesleyan University's commencement ceremony.

From the Associated Press: Filling in for Sen. Edward M. Kennedy and tying himself to the family's legacy, Democratic presidential candidate Barack Obama urged college graduates Sunday to "make us believe again" by dedicating themselves to public service.

"We may disagree as Americans on certain issues and positions, but I believe we can be unified in service to a greater good. I intend to make it a cause of my presidency, and I believe with all my heart that this generation is ready and eager and up to the challenge," Obama told Wesleyan University's Class of 2008.

Video: Barack Obama's Commencement Speech at Wesleyan University