Jason Lyndon, pictured below, a web developer from Atlantic Road, attended U2's gigs at the Don Valley and Millennium Stadiums as a representative of the ONE organisation – and as a thank you was given the 'best seat in the house' to watch the show.
After signing up fans of the band to join ONE, which campaigns against extreme poverty and preventable disease, Jason then found himself walking on stage with his heroes as they performed on their 360 Degree World Tour.
When he was invited to volunteer for the political group to sign up new recruits at U2 gigs, he jumped at the chance. But he never thought he would become part of the concert.
"It was a unique experience and we were made to feel part of the tour," Jason said.
"I had a ticket for the gig in Sheffield but agreed to help ONE.
"After signing up new members before the gig, we had the best seats to watch the concert. At one point I was just three feet from Bono."
Jason, other ONE volunteers and members of Greenpeace were then invited on stage, carrying masks with the face of Aung San Suu Kyi, the deposed leader of Burma, who has spent much of the last 20 years under house arrest.
"At Cardiff we went into the stadium through the same entrance as the band," the 34-year-old said.
"It was one of U2's best gigs for eight or nine years.
"Going up on stage was a little bit daunting but quite exciting.
"At the same time we were involved in something that can do real good to try and get Aung released."
To find out more about ONE go to www.one.org.