Some specific GA info that the venue is sending out (thanks to EducateMyMind for forwarding) :
"Guests who have general admission tickets to the U2 concert and want to line up in advance will be directed to line up on the Northwest corner of 1st Street & Madison. However, that is not our property and is a public right of way so individuals who are lined up cannot block the sidewalk.
At 9am on the day of the show, we will distribute numbered wristbands to guests who are already in line.
Those guests will not need to wait in line all day but we encourage them to return to the Pavilion, located on 1st Street & Jefferson Street, at 4pm so we can get individuals back into the correct order.
Guests with a numbered wristband who arrive after 5pm will not be guaranteed their place in line.
Once doors open, guests will have their credit card scanned, a ticket stub printed and they will use that ticket stub to get the wristband for the floor.
Please let us know if you have any additional questions and we hope you enjoy the concert!"