The Doppelgangers were, back in about 93/94 the "Official" U2 tribute band, actually endorsed by the band themselves as I understand it. From memory they feature heavily on the Stay (Faraway So Close) video. The band I was in back in the UK played with them at our then major local music venue, before we were signed, and they said they had met U2 and were using the same equipment the band used.
Were they any good? Yeah they were ok. 'Bono' was a bit fat and didn't sound like him very much but the music was good and they put on a really good show. I asked them very nicely during soundcheck to let me play Bad and Streets with them during the show (on bass) and they let me. 'Larry' also sung Dirty Old Town that night too. I still have the press cuttings advertising it in my scrapbook, obviously only because my band were involved!!