Please forgive my writing in English!
During U2’s 1985 Unforgettable Fire tour, The Edge called me to talk about the origins of U2, as well as his guitars, techniques, tunings, and gear, and how to turn musical limitations into advantages. When I asked him about slide, Edge said: "I use metal chrome slides. I use it on the middle finger. You know, a lot of slide guitar players would use the trailing finger [the finger behind the slide] to stop any resonance on the strings behind the bottleneck. I actually don’t do that. I control some of that problem with my picking hand, but the rest I actually quite like. I quite like the effect that it gives, a sort of strange ambience." He also talked about playing lap steel and the strange tunings he's invented.
Other highlights are when he talks about how he and the rest of U2 turned their musical limitations into a sound all their own, as well as how to break out of playing clichés. If you’re interested in seeing more, I’ve transcribed and posted the entire conversation here:
http://jasobrecht.com/u2%e2%80%99s-edge-talks-guitars-gear-techniques/
Hopefully, some kind person will translate this post into French for me. Merci!