U2 are certainly putting the emphasis on the 'experience' part of their 'Innocence + Experience' tour - as in, they're giving some fans an experience to remember.

So far, Bono and co. have invited a U2 tribute band and a fan who had a homemade sign asking to play guitar to guest on a song or two.

Last night, it was the turn of a celebrity fan to do the honours - more specifically, Jimmy Fallon, who sang 'Desire' on stage with the Dubliners at Madison Square Garden in New York.

The TV host, who recently injured his finger in a freak accident at home, held up a sign saying 'Singer with a broken finger' and was invited on stage - putting in a decent Bono impression, all told.

The Roots, Fallon's in-house band on The Tonight Show, also made an appearance on 'Angel of Harlem'.

Watch the fan-shot footage below: 

Here's a closer view:

And here's 'Angel of Harlem' with The Roots: