Hollywood star Scarlett Johansson has hailed U2 rocker Bono as a genius for coming up with the idea for the new Red campaign, which will raise money for causes in Africa.

The Lost In Translation actress and face of the innovative charity label insists she was blown away with the idea, and couldn't believe her luck when he asked her to take part in the Global Fund.

She says, "I met Bono a few years ago. I had a friend who was working for him, and when U2 came to play in New York, I asked if I could get tickets.

"I met him at the after-show dinner, and he was hilarious - and very mischievous.

"I was surprised at how available he was after seeing him so God-like on stage. After doing this amazing show, he came and talked to us about all the things he was doing, in particular the Global Fund.

"So when he called me and asked me to do this shoot, it sounded too good to be true.

"The whole project is unbelievable: when he told me about the (dedicated Red) American Express card, I thought, 'How did he manage to make that happen?'

"He is a symbol of everlasting coolness."