Making her debut as a commencement speaker before a crowd of 12,000 on Saturday, FIrst Lady Michelle Obama praised graduates at the University of California, Merced, the state's smallest, youngest public university.

She urged the 493 members of the school's first full graduating class to give back to their communities:

"Many of you may be considering leaving town with your diploma in hand, and it wouldn't be unreasonable," she said. "By using what you've learned here...