IF theres one thing i'm sure about with edge's tone on staring at the sun, is that there's no delay. Does anyone else know what effects he uses? U2sound.com is down, otherwise i'd look there.
oh, i bet there is delay! live i'm pretty sure he uses delay. the tone is really really fat and juicy, maybe a lovetone meatball? i know you need a humbucker gutiar, and probably a hollow body one like a Gibson ES.
There's a movie on that site where the bands is sound checking SATS. By looking at that, I'm pretty sure he uses the same fender that he does on discotheque, I could be wrong though. Maybe he uses a humbucking guitar in studio?