Once upon a time the world was one, at least geographically. All land masses on Earth were united in a supercontinent that scientists have named Pangaea.

The unity Pangaea Day seeks to bring about will be done electronically — with movies, music, and speeches to be broadcast on television, the internet, and on cell phones over four hours. The goal is ambitious: to see life through each other's eyes.

The idea came from documentary filmmaker Jehane Noujaim, who grew up in Cairo. Two years ago she won a TED Prize in 2006, and decided to use the platform it gave her to create a global event to help people look beyond the stereotypes of other cultures.

Noujaim, who produced the 2004 documentary Control Room, which contrasted how Western and Middle Eastern news media covered the invasion of Iraq, said she wants to use the power of film to "bring the world together" for a day.

So she and the Pangaea Day organizers solicited short films from people around the world to capture their communities and express their beliefs. They selected 24 films from the more than 2,500 submitted from 102 countries. Nokia provided mobile phones with video camera capabilities to allow people to remote or poor areas to create shorts and submit them digitally.

The event's execution will be equally ambitious. It will span continents with live broadcasts taking place simultaneously at the pyramids in Egypt, and in Kigali, Rwanda; London; Los Angeles; Mumbai; and Rio de Janeiro. (A map of events can be found here.)

Some celebrities, including CNN correspondent Christiane Amanpour, will speak. Bob Geldof and others, including The Eurythmics' Dave Stewart (below), will provide live music.

For people not near one of the live venues, the event, which begins at 18:00 GMT, will be streamed live over the internet in eight languages. Anyone can sign up to host a festival site — which can mean simply inviting a few friends over to watch.

So where does this "global campfire of shared stories" — as some organizers call the event — go from here? Noujaim and some of her celebrity advisors like Goldie Hawn and Cameron Diaz concede that movies can't change the world. But the people watching them can.

After Saturday, Pangaea Day organizers have pledged to actively support community building around the world by connecting viewers who were inspired by the broadcasts with organizations working to bring about tolerance and understanding across cultures.

by Elizabeth Olson