Will.I.Am of the Black Eyed Peas put the project together in two days

Actress Scarlett Johansson and jazz legend Herbie Hancock sing lines in the music video, created by Will.I.Am from pop group Black Eyed Peas.

The rapper was inspired to create the song, Yes We Can, after the Democratic candidate spoke in New Hampshire.

"That speech affected and touched my inner core like nothing in a very long time," Will.I.Am said.

The result was produced in two days and has been watched by millions of internet users.

Others participants include R&B singer John Legend, rapper Common, basketball legend Kareem Abdul-Jabbar, CSI star Adam Rodriquez and Pussycat Dolls frontwoman Nicole Scherzinger.

Obama approval

Will.I.Am explained: "It was as if he was talking to and defending everything that made me who I am.

"I took that speech, and I wanted everyone else to be inspired by that speech as I was."

It has gone down well with Mr Obama.

The candidate has had it posted on his website and personally recommended it to journalists following his campaign.

But Will.I.Am said Mr Obama's team has not been in touch personally: "They have more important things than to be contacting me to say thank you.

"If they had time to call me, I'd be panicking."

John Mellencamp with former Democratic contender John Edwards

Four years ago, the Black Eyed Peas supported Democratic presidential candidate John Kerry.

Meanwhile, songs by rocker John Mellencamp have been dropped from Republican contender John McCain's events after the musician's publicist questioned their use.

"Are you sure you want to use his music to promote Senator McCain's efforts?" asked Bob Merlis.

"Logic says that the facts might prove to be an embarrassment, were they to be circulated widely," he added.