Whoa... that actual effect! If you can pull it off, I'd like to see you do it. It's actually a mix of vocals and some crazy guitar setup, I'm afraid only the Edge will be able to accurately replicate it (and even he probably doesn't remember, as they've just play it over the P.A. whenever they play UTEOTW it live).
...That is unless you're talking about that slidey bit he does over it live (especially noticable on Zoo TV). If that's what you mean, then that's just a slow slide up the thick E string from the 2nd to the 15th fret.