I watched the video on youtube from their July 2nd show. Bono spots a guy in the audience who is holding a sign he wants to play a song for his wife. Bono spots him, has security help him on stage and the guy plays guitar for their song, All I Want Is You. The rest of the band comes out and finishes the song with the fan and Bono. Bono then gives the guy the guitar as well.
Check it out on youtube!
Check it out on youtube!