I think, Mick, what we don't tend to have is a standard phrase to thank someone for thanking us, if you know what I mean. So if someone thanks me for something, I'm more likely to say "that's okay" or "don't mention it" than "you're welcome".

Not all the time, but a lot of the time when I've heard it said in the States on my visits, it's sounded like more of a reflex than something that's said with any sincerity. 'Specially in shops. Still, there's nothing wrong with social graces and niceties...