Jack Black cameos at Brand O2 show

Hollywood stars Jack Black and Jason Segel made cameos at Russell Brand's O2 show on Friday.

After Brand finished his stand-up show for the 16,000 crowd, he told the audience that they would be extras in his new film Get Him To The Greek.

Get Him To The Greek is a spin-off from 2008 comedy Forgetting Sarah Marshall, focusing on Brand's rock star character Aldous Snow. Jonah Hill, Rose Byrne, P. Diddy and Elisabeth Moss are also in the cast.

Brand returned to the stage dressed as Snow and performed the tracks 'I Am Jesus' and 'Inside Of You'. The scenes will appear in the movie and a DVD of the gig, which is being released at Christmas.

During the interval when Brand was getting changed, Black and Segel performed the song 'Dracula's Lament' from Forgetting Sarah Marshall.