SEAN PENN is fighting the war in Iraq, poverty, homelessness and saving the environment, all from a bus.

The actor, who baffled many when his name showed up on the lineup for the Coachella Valley Music & Arts Festival underway this weekend in southern California, plans to board a fleet of biodiesel buses and take about 300 people on an 2,880-kilometer trek across the United States, ending in New Orleans.

Penn's brainchild, the Dirty Hands Caravan, takes off today and is expected to arrive in the Big Easy on May 4 for the city's annual jazz festival.

"I see this as a reckoning," said Penn, who's set to appear twice at Coachella yesterday. "My generation and those that came before have to recognize the numbing of incentive that we've passed on to the change hungry, imaginative, smarter than us youth of today."

Penn said he's simply providing the wheels and the young people are leading the ride.

"The Dirty Hands Caravan seeks to empower young people to stand up for what they believe in, with its longevity based on inspired individuality and pride," he said.

As the biodiesel buses make their way across U.S. cities, the plan is to have its members volunteer for local organizations or do whatever they feel inspired to do. (SD-Agencies)