Keira Knightley Keira Knightley Just when you thought American Idol couldn't get any hotter...

The US reality talent show gears up for its first celebrity edition.

And taking centre stage for the special show are Britain's hottest stars.

It's American Idol Gives Back, a two-night extravaganza all in the name of charity.

Keira Knightley, Hugh Grant, Daniel Radcliffe and Helena Bonham Carter are some of the stars who will be taking part.

They'll be taking the stage with the likes of Teri Hatcher, Forest Whitaker and Gwen Stefani.

The event will raise cash to help victims of 2005's Hurricane Katrina, as well as to raise money for various children's charities in Africa.

Hugh GrantHugh Grant We wonder how judge Simon Cowell will react to his fellow celeb mates?