Kristin Bell, Rachel Bilson and Pete Wentz Host Event to Benefit Invisible Children

Kristin Bell sporting the Guess Invisible Children T-shirt at last night's event in Beverly Hills.

I have to admit, Kristin Bell impressed me last night. I had heard of her involvement with the nonprofit organization Invisible Children but had looming doubt that she—or any of the other celebrities lending their name to the cause—truly understood the politics behind the 24-year-long war in northern Uganda and the urgent need to end the rule of the Lord Resistance Army's rebel leader, Joesph Kony. I was wrong.

Bell, who co-hosted a Vanity Fair event last night with Rachel Bilson and Pete Wentz at the Guess flagship store in Beverly Hills, answered the reporter's questions with heart and a true understanding of the politics and plight of the children in the war-torn region, who live in constant fear of being abducted and forced to kill or be killed. The event marked the launch of a new line of organic T-shirts (the cotton is grown and harvested in Uganda) that will benefit Invisible Children.

The situation in northern Uganda is one of the worst humanitarian crisis in the world, Bell said, citing the UN Ambassador for Humanitarian Affairs. (I'm telling you, the girl knows what she's talking about.) The organization, which we featured earlier this year 'cause they're so amazing, was started after three young filmmakers traveled to Africa in 2003 'in search of a story.' What they found both "disgusted and inspired" them. After returning to the US, they made the documentary Invisible Children: Rough Cut, which showed the reality of the children caught in the midst of the civil war. So, what does this movement say about the power of media?

Invisible Children supporter Pete Wentz.

"It says a lot about how film and storytelling can be used to bring about social change," Bell told me. "Never underestimate a good story. The great thing about the guys that made Invisible Children is that they went to film school, they're excellent storytellers and they found an unbelievable story and were able to use their filmic techniques to keep you interested, and almost go against the grain of doing a documentary about child soldiers. You don't cry through the whole thing—you laugh through a lot of it, which is really important because I can understand how people seeing a cause like this could feel guilty, or turned off or not know what to do. And what I love about [the filmmakers] is that they inspire you, they don't make you sad."

Bell, who was donning both the Invisible Children T-shirt and bracelets, has been a champion of the cause, traveling to Washington twice this year to lobby Senators on the issue.

"When I lobbied this year I believe it was successful because we met a lot of senators, representatives and congressmen and were able to have personal conversations with them, which I think is so rare nowadays," she said. "They're so used to getting emails; they don't even get written letters anymore. We were able to stand right outside of the congressional floor to hand out flyers about what we were doing and meet senators face-to-face. We told them 'We are representing the youth of America, and we want you to be involved in this.' "

Rachel Bilson talks to PopSugar about why she supports Invisible Children.

Follow Bell's lead and tell your member of Congress to sponsor the LRA Disarmament and Northern Uganda Recovery Bill. The shirts are available for purchase at Guess.com and in retail stores across the country starting early November. (Stock up for the holidays!) One-hundred percent of proceeds go to Invisible Children.