George Clooney, his wife Amal Alamuddin and Cindy Crawford and her businessman husband Rande Gerber were spotted together at U2's concert at the Forum in California over the weekend. 

As the Dublin band launched into their final song of the night, I Still Haven't Found What I'm Looking For, the four famous friends sprang to their feet.

LA-based gossip site TMZ has run some footage of the moment. 

Noel Gallagher and Billie Joe Armstrong of Green Day were also recent famous fans attending U2 gigs in the US.

Bono and Clooney are long-time friends and the singer attended the Venice wedding of George and Amal last year.