I lifted the following tale from Viola Wilkins' blog on the Aussie IWW website -

Five British surgeons are sharing a table for dinner following a conference in London.
The first, a Manchester surgeon, says: 'I like to see accountants on my operating table, because when you open them up, everything inside is numbered.'
The second, a Liverpool surgeon, responds: 'Yes, but you should try electricians! Everything inside them is colour coded.'
The third, a Newcastle surgeon, says: 'No, I really think librarians are the best; everything inside them is in alphabetical order.'
The fourth, a Birmingham surgeon, chimes in: 'You know, I like construction workers best...those guys always understand when you have a few parts left over.
But the fifth, a Glasgow surgeon, shuts them all up when he observes, You're all wrong. Politicians are the easiest to operate on. They have no guts, no heart, no balls, no brains and no spine, and the head and the arse are interchangeable.