Ken Burns' "The Civil War" on my iPhone? Too Cool...

apparently, there's an app for that! And it's Free...check out the PBS app for iphone and ipad at the Apple App Store.

Don't forget Austin City Limits on Saturday night...Grammy Award-winners the Foo Fighters rock the ACL stage with songs from their latest album, Echoes, Silence, Patience & Grace...10pm

How does the simple act of planting trees lead to winning the Nobel Peace Prize? In 1977, Wangari Maathai of Kenya suggested rural women plant trees to improve a degraded environment. Under her leadership, their tree-planting grew into a nationwide movement that achieved much more than that...and brought Maathai the Nobel Peace Prize in 2004. Independent Lens...11pm.

Watch the full episode. See more Austin City Limits.