Sean Penn seen at State Dept. pre-Nerd Prom

Laura Rozen

Spotted at the State Department today by a tipster: Sean Penn.

What was the actor/director/philanthropist doing at Foggy Bottom? It's not totally clear.

"Apparently he has meetings all over D.C. today--the White House, State, Pentagon," one State Department official said.

Penn is in town to attend Saturday's White House Correspondents Association dinner--the event known to the Washington press corps as "Nerd Prom"--as a guest of Mother Jones magazine.

One guess as to Penn's business with government officials: his recent humanitarian work in Haiti. He was recently awarded the Producers Guild of America 2011 Stanley Kramer Award for his efforts in the Caribbean nation, and co-founded the J/P Haitian Relief Organization, which is trying to help Haiti, the poorest country in the western hemisphere, recover from its Jan. 2010 earthquake.

Secretary of State Hillary Clinton and former President Bill Clinton have a particular love of Haiti, and Clinton's counselor Cheryl Mills has been spearheading the department's work on post-quake relief there.

Penn is also executive producer of a new documentary, "Love Hate Love," on three families whose lives were affected by terrorism, which premiered in New York at the Tribeca Film Festival earlier this week.

(Penn at the premiere of the documentary "Love Hate Love," at the Tribeca Film Festival April 26, 2011: Dave Allocca, AP Photo/StarPix)