WASHINGTON -- On the eve of Barack Obama's inauguration more than 50 celebrities have teamed up on MySpace to record videos making a "pledge of service" to the next president of the United States.

Among the celebrities who recorded videos for The Presidential Pledge project, sponsored by MySpace and actor Ashton Kutcher's Katalyst Media, are singers Sean P. "Diddy" Combs and actresses Cameron Diaz and Eva Longoria.

Others making pledges include Will.i.am of the Black Eyed Peas, Anthony Kiedis of the Red Hot Chili Peppers, actresses Marissa Tomei, Courtney Cox Arquette, Lucy Liu and Laura Linney and actors Jason Bateman and Tobey Maguire.

The videos, which are available at myspace.com/presidentialpledge, were directed, produced and edited by Kutcher's wife, actress Demi Moore.

Viewers are also invited to record their own personal pledge and upload it to the site.

"The ultimate goal is to motivate the MySpace community to create their own pledges to help bring about the change inspired by Obama's Campaign," MySpace said in a statement.

"The Presidential Pledge is a platform for people across the nation and throughout the world to make a first person commitment of service to our new President, articulating a specific intent or action to become an agent of positive change," said Kutcher.

Among the pledges is Combs's commitment to "turn the lights off," "Desperate Housewives" star Longoria's promise to "plant 500 trees." "Friends" star Cox Arquette for her part pledges to "help end hunger in America."