Thanks chaps. We adapted some songs to re-distribute what the guitar did elsewhere, eg we play Dee Doo Doo Doo by The Police and the bass does the guitar part in the outro. Others we thought would work (Easy by The Commodores) fell down because the guitar solo was, in our view, too integral to the song.
Chris - there is a dialogue of sorts in the band just now that reflects your view about putting songs through a "treatment" or whether we just find songs that were recorded on bass/drums/keys. I suspect we would be playing a lot of Ben Folds and little else though, so it'll likely come down to a mixture of the two approaches. Casapete has a good point about the audiences though - this is primarily a drunken pub audience in Glasgow!