As U2 continue their '360 Tour', the band paid tribute on stage to Boyzone star Stephen Gately, dedicating one of their songs to the singer.
According to their website, the band dedicated 'Unforgettable Fire' to the memory of Gately at both their Houston and Dallas concerts.
Speaking about the singer, Bono said the 33-year-old was "a beautiful spirit and a bright flame".
Millions of U2 fans around the world will be able to watch the band live in concert this weekend as their California show on Sunday night will be streamed free of charge on the internet.
However Irish viewers will have to stay up very late to catch the sold-out show from the Pasadena Rose Bowl, outside Los Angeles, which is due to be aired on YouTube at 3.30am Irish time on Monday morning.
The concert is the penultimate date of the band's '360 Tour' this year, although more dates will follow in 2010.