Like any of the band's 80,000 screaming fans that night, his then girlfriend naturally took a snap to capture the excitement.
Unlike other gig-goers however, it doesn't show the young couple smiling out from the crowd, or even Bono and his bandmates doing their thing on stage.
Instead, it freeze-framed Darragh in the grip of an internet fixation – recording the gig on one gadget and tweeting non-stop on another.
Reformed Twitter addict Darragh (34) who lives in Dublin 8, admits he barely remembers going to such events.
"I've gone to things where I was videoing or tweeting or whatever, and I don't remember that I've been there, because I wasn't really there," says Darragh, a community manager with WorldIrish.com.
"I was so eager to communicate to other people that I wasn't really experiencing it. That photo was a huge wake-up call for me.
"I have this love/hate relationship with the internet," he explains. "I need to use it for work, but I became a little bit too dependent on it.
Want to join in? Save this to your To-dos or mark as Done.