Sean Penn is fighting the war in Iraq, poverty, homelessness and saving the environment, all from a bus. After appearances this weekend at the Coachella festival, the actor plans to board a fleet of b

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 this year's Coachella Valley Music & Arts Festival in Indio, Calif., plans to board a fleet of biodiesel buses and take about 300 people on an 1,800-mile trek across the U.S., ending in New Orleans.

Penn's brainchild, the Dirty Hands Caravan, will take off Monday and is expected to arrive in the Big Easy on May 4 for the city's annual Jazz & Heritage Festival.

"I see this as a reckoning," said Penn, who's set to appear twice tomorrow at Coachella. "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.

With the goal to "encourage individuals to take individual actions," the caravan will stop at campgrounds where they'll be joined by musicians, activists, artists, filmmakers and guest speakers.

"I invited Sean to speak at Coachella, and he took it one step further and came back to me with this idea," Coachella organizer Paul Tollett said. "The entire Coachella team is excited to launch this journey at this year's festival."